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# The "City" Under Khafre: What The Italians Claim, And What's Left Of It
- URL: https://theegyptfiles.com/city-under-khafre/
- Published: 2026-09-19T19:46:23.000Z
- Updated: 2026-09-20T13:46:47.000Z
- Description: A radar team says it found eight spiral shafts and two 80-metre cubes under Giza. The paper behind their method has been retracted. The full file: the claim, the physics, the experts and what would settle it.
- Author: J E Cowie
- Tags: Khafre Project, Giza, Pyramids, Case files, News

*A satellite-radar team says it found eight spiral shafts and two 80-metre cubes beneath Giza. The peer-reviewed paper that applied their method to the Great Pyramid has since been retracted. This is the full file.*

```
CASE FILE: THE KHAFRE PROJECT
CLAIM:    Eight spiral-wrapped shafts, two 80 m cubes and five multi-level
          structures beneath the Khafre pyramid, Giza
SOURCE:   Corrado Malanga, Filippo Biondi, Armando Mei
FILED:    March 2025
STATUS:   UNVERIFIED. The team's 2022 Great Pyramid paper was
          retracted on 10 August 2026

```

![The Khafre Project's 3D model of its claimed spiral shafts and cubes](https://theegyptfiles.com/content/images/2026/09/01-khafre-claim-shafts-cubes-1.png)

The team's 3D model of the claimed shafts (left) and cubes (right). © Khafre Project, from the team's March 2025 press abstract. These illustrate a claim; they are not data.

## The short version

In March 2025 a small Italian-led team said satellite radar had revealed a vast structure beneath the pyramid of Khafre. The story reached the Daily Mail, the New York Post, Joe Rogan and, in August 2026, the History Channel. It has not been peer-reviewed, and I found no independent replication. On 10 August 2026 the journal that published the team's 2022 paper applying the same method to the Great Pyramid retracted it.

## What the team claims

The Khafre Research Project is Corrado Malanga, Filippo Biondi and Armando Mei, with Nicole Ciccolo as communications lead. Malanga is an organic chemist at the University of Pisa (retired, according to National Geographic). Biondi is a telecommunications engineer who was a visiting professor at the University of Strathclyde when the 2022 paper was published. National Geographic notes that Malanga has published books about aliens, and Snopes cites his well-documented interest in UFO and alien-abduction research. That proves nothing either way; the method has to stand on its own.

Their press abstract was issued for a press conference in mid-March 2025 (outlets date the conferences anywhere from 15 to 23 March). It describes:

- **Five multi-level structures** inside the pyramid, above Belzoni's Chamber, joined by geometric pathways. Each has five horizontal levels and a sloping roof, and the team says each matches the Zed, its name for the stack of granite slabs above the King's Chamber in the Great Pyramid (the relieving chambers, in Egyptological terms).
- **Eight hollow cylindrical shafts** in two parallel rows, each surrounded by a spiral pathway, descending 648 metres.
- **Two cubes of about 80 metres per side**, where the shafts merge.
- Further structures reported down to about two kilometres beneath the plateau, under all three pyramids.

National Geographic reported that the team dates them to roughly 38,000 years ago.

The abstract says the work used publicly available radar data from the commercial satellite operators Capella Space and Umbra. Biondi told Joe Rogan (episode 2443, January 2026) that the team had run more than 200 scans across several satellite systems, all with consistent results.

## How the method is meant to work

Satellite radar (SAR) is a surface-imaging tool. How far it sees into the ground depends on wavelength and material. In the early 1980s, NASA's Shuttle Imaging Radar used L-band radar to find buried river channels under one to two metres of very dry Saharan sand, a landmark result. For X-band, the band used by satellites such as COSMO-SkyMed and Capella, one review of the literature puts penetration in dry sand at roughly 5 to 30 centimetres. Ground-penetrating radar, the tool built for looking underground, tops out at 15 to 20 metres by Biondi's own account.

The team's answer is not to penetrate at all. Biondi's method reads tiny vibrations of the structure from the radar's Doppler signal, treats them as sound, and inverts them into a 3D image. He told Rogan the technique isn't penetrating anything; it is picking up vibration information at the surface that carries information about what lies below. The abstract of the team's own 2022 paper opens by conceding that satellite radar normally can't observe inside solid bodies.

Biondi's evidence for the method is a set of benchmarks: the Gran Sasso physics laboratory inside an Italian mountain, the inspection tunnel and turbines of the Mosul dam, the Gotthard rail tunnel, and the Osiris shaft at Giza. These come from his own presentations, not independent testing. He told Rogan the method is his invention. He said he is under an NDA and so could say little about a second patent, which he said was filed in the US the previous day. He also said he'd be happy for other groups to replicate the work.

The 2022 paper's reference list cites earlier peer-reviewed work applying related vibration-based radar methods to ships, the Mosul dam, bridges and volcanoes, including a volcano paper claiming imaging to about 3 kilometres. I haven't assessed that work, and the retraction doesn't cover it.

![The team's 3D model beside a tomographic radar image](https://theegyptfiles.com/content/images/2026/09/02-khafre-model-vs-radar.png)

Left: the team's 3D model. Right: a tomographic image from the team's abstract. © Khafre Project. National Geographic noted that comparing the published radar images with the reconstructions shows how much artistic licence is being taken.

## The paper underneath it: retracted

The Khafre claims build on a 2022 paper in the journal *Remote Sensing*, "Synthetic Aperture Radar Doppler Tomography Reveals Details of Undiscovered High-Resolution Internal Structure of the Great Pyramid of Giza". It claimed the method had mapped a network of rooms, corridors and tunnels inside Khufu's pyramid, including features nobody had recorded.

On 10 August 2026 the journal retracted it. A reader raised concerns about the methodology, and the journal's investigation, in its words, "confirmed serious methodological flaws and statistical errors" that undermine the paper's conclusions. The authors disagree with the decision. Newsweek notes the notice does not allege fabrication or misconduct.

Retraction Watch adds that Lawrence Conyers, a ground-penetrating radar specialist at the University of Denver, was asked to review the original paper. He told the editor he would not recommend publication unless a second reviewer who understood the mathematics was found. He told Retraction Watch the micro-vibration explanation is technically unsound: "I don't care what magical properties you are using, it just doesn't work." Biondi and Malanga did not respond to Retraction Watch's requests for comment. Two weeks after the retraction, Biondi shared the History Channel episode on X.

A retraction doesn't prove nothing is down there. It means the journal no longer stands behind the paper's application of the method to the Great Pyramid. The Khafre claims never had even that: they have not been peer-reviewed at all.

![3D reconstruction of the Great Pyramid's interior from the retracted 2022 paper](https://theegyptfiles.com/content/images/2026/09/03-khufu-fig22-3d-reconstruction.png)

Figure 22 from the retracted 2022 paper: the team's 3D reconstruction of the Great Pyramid's interior. Biondi & Malanga, Remote Sensing 2022, 14(20), 5231, CC BY.

![The team's 3D model of the Great Pyramid beside its radar tomographic measurement](https://theegyptfiles.com/content/images/2026/09/04-khufu-fig43-model-vs-radar.png)

Figure 43 from the same paper: the team's 3D model (left) beside the radar-derived tomographic measurement (right). Biondi & Malanga, Remote Sensing 2022, 14(20), 5231, CC BY.

## What the experts say

**Sarah Parcak**, a satellite archaeologist at the University of Alabama at Birmingham, says single-aperture radar can't see through rock, and that with enough manipulation she could make satellite imagery look almost any way she wanted. National Geographic quotes her: "SAR data can't see through rock, period."

**Lawrence Conyers** told the Daily Mail the claim of a vast city is a huge exaggeration. On the 2022 Great Pyramid paper, he told Retraction Watch it is physically impossible for satellite radar to penetrate the pyramid, reflect off internal structures and return to the sensor.

**Salima Ikram**, professor of Egyptology at the American University in Cairo, told Decrypt there is no peer-reviewed paper or raw data to evaluate, and that the technology doesn't appear capable of what the team claims. She said Egyptian authorities confirmed they had not granted the team permission to conduct any work at the site.

**Zahi Hawass** called the claims baseless and said no permits were granted for such a study. The team's data came from satellites, not work on site.

**Flint Dibble**, an archaeologist at Cardiff University, points to the water table. A 2019 study put it only a few dozen metres below the Giza plateau, so structures two kilometres down would always have been underwater. He also joked that the reconstruction looks based on the reactor room from *Total Recall*.

**Lynn Dodd**, a University of Southern California professor of religion and spatial science, told Decrypt that existing surveys, remote sensing and excavation have found nothing like the deep structures described. The voids archaeologists do find near pyramids are usually construction features such as ramps and robber shafts.

**Snopes** found no credible evidence for the claim. It also reported that one widely shared cross-section image scored a 99.9% chance of being AI-generated on Hive Moderation. That was a single circulating image, not the team's own models.

## How hidden spaces in the pyramids have actually been found

The confirmed voids in the Great Pyramid were found with cosmic-ray muons, which are partly absorbed by stone depending on how much of it they cross. The ScanPyramids project reported the Big Void in *Nature* in November 2017: at least 30 metres long, above the Grand Gallery, the first major inner structure found in the pyramid since the nineteenth century. It was seen with nuclear emulsion films, confirmed with scintillator detectors, then re-confirmed with gas detectors outside the pyramid. The North Face Corridor, behind the Chevron on the north face, was first flagged by muons in 2016 and 2017\. Ground-penetrating radar and ultrasound surveys between 2020 and 2022 found a strong air anomaly at the same spot, and a 2023 muon study pinned it down to about 9 metres long and 2 by 2 metres in section.

The pattern is different physics giving the same answer. The Khafre claim is one team's processing of one kind of data.

Khafre has been tried before. Luis Alvarez's team searched it for hidden chambers with muon detectors in 1970 and found no new structures. A collaboration called ScIDEP is building muon telescopes to scan Khafre from inside the burial chamber and from outside. Its 2025 paper describes a prototype being commissioned in Alexandria, and a June 2026 conference abstract says its detectors were still under construction. I found no pyramid data from it.

**Don't confuse it with Hawass's announcement.** Hawass has said a roughly 30-metre passage inside Khufu's pyramid, ending at a door, will be announced in 2026\. He says it comes from his own team's work, using thermal imaging, 3D mapping, muon radiography and robots. It is separate from the Italian team's work, and as of September 2026 I found no published data or announcement for it.

## The "psychedelic pyramid" claim

On Rogan, Biondi carried the same thinking into the Great Pyramid. He described the Zed, the stack of granite slabs above the King's Chamber, as "a low pass filter made by stones". In his account the top of the Zed acts as an antenna for vibration, and the last layer passes it into the granite box in the chamber below, usually called the sarcophagus. Rogan suggested a person lying in it would have a psychedelic experience. Biondi agreed, saying the person might have had an out-of-body experience induced, and that this was not scientifically recognised. He said the filtering effect came from a simulation he ran himself, and that he doesn't know what happened to anyone in the box.

I found no published simulation of the Zed as a filter. The 2022 paper does float an acoustic-resonator interpretation of the pyramid, invoking Helmholtz resonators and Quincke-tube acoustic filters, but I couldn't confirm it contains the simulation Biondi described to Rogan. The Zed itself is described in that paper, which has now been retracted. The standard explanation of the relieving chambers is that they spread the weight of the masonry above the King's Chamber.

![Section drawings of the Great Pyramid showing the Zed above the King's Chamber](https://theegyptfiles.com/content/images/2026/09/05-khufu-fig02-zed.png)

The Great Pyramid's known interior (a), with the Zed labelled 1, and the Zed in section (b, c). Biondi & Malanga, Remote Sensing 2022, 14(20), 5231, CC BY.

## What would settle it

- **Release the method.** The satellite data is public, according to the team's abstract. If the processing were disclosed, anyone could rerun it. Biondi says it is proprietary and patented.
- **A conventional survey.** Biondi told Rogan the plan is a proposal to the Egyptian authorities, with the University of Ferrara, using established ground techniques on shafts between the Sphinx and Khafre's pyramid. He estimated about $20 million, with robots and drones to clear them. At the time of the interview it had not been submitted, and I found no update.
- **Independent muon scans of Khafre**, which the ScIDEP collaboration is still preparing.

A drill core or a ground-penetrating radar line in the right place would do more than any number of press conferences.

## Where it stands

I found no report of anything dug, drilled or independently scanned that confirms the claims. The peer-reviewed paper applying the method to the pyramids has been withdrawn, and the Khafre claims that followed have never been reviewed at all. The only thing to have gone down so far is the paper.

## Sources

- Team's press abstract, March 2025 (copy hosted by a third party; I could not find the original host): [https://fightingmonarch.com/wp-content/uploads/2025/04/official-khafre-project-press-release.pdf](https://fightingmonarch.com/wp-content/uploads/2025/04/official-khafre-project-press-release.pdf?ref=theegyptfiles.com)
- Retraction notice, *Remote Sensing* 2026, 18(16), 2679: [https://www.mdpi.com/2072-4292/18/16/2679](https://www.mdpi.com/2072-4292/18/16/2679?ref=theegyptfiles.com)
- Retracted paper, *Remote Sensing* 2022, 14(20), 5231: [https://www.mdpi.com/2072-4292/14/20/5231](https://www.mdpi.com/2072-4292/14/20/5231?ref=theegyptfiles.com)
- Retraction Watch: [https://retractionwatch.com/2026/08/31/retraction-corridors-inside-great-pyramid-giza/](https://retractionwatch.com/2026/08/31/retraction-corridors-inside-great-pyramid-giza/?ref=theegyptfiles.com)
- Newsweek on the retraction: [https://www.newsweek.com/bombshell-great-pyramid-of-giza-study-retracted-12412886](https://www.newsweek.com/bombshell-great-pyramid-of-giza-study-retracted-12412886?ref=theegyptfiles.com)
- National Geographic, Candida Moss, 16 April 2025: [https://www.nationalgeographic.com/history/article/is-there-a-secret-city-under-the-pyramids-](https://www.nationalgeographic.com/history/article/is-there-a-secret-city-under-the-pyramids-?ref=theegyptfiles.com)
- Decrypt, 25 March 2025: [https://decrypt.co/311432/ancient-mystery-modern-hoax-experts-debunk-giza-pyramid](https://decrypt.co/311432/ancient-mystery-modern-hoax-experts-debunk-giza-pyramid?ref=theegyptfiles.com)
- Snopes: [https://www.snopes.com/fact-check/pyramids-of-giza-new-discovery-structures/](https://www.snopes.com/fact-check/pyramids-of-giza-new-discovery-structures/?ref=theegyptfiles.com)
- Joe Rogan Experience #2443, Filippo Biondi (transcript): [https://podcasts.happyscribe.com/the-joe-rogan-experience/2443-filippo-biondi](https://podcasts.happyscribe.com/the-joe-rogan-experience/2443-filippo-biondi?ref=theegyptfiles.com)
- ScanPyramids Big Void, *Nature* 2017: [https://www.nature.com/articles/nature24647](https://www.nature.com/articles/nature24647?ref=theegyptfiles.com)
- ScanPyramids North Face Corridor, *Nature Communications* 2023: [https://www.nature.com/articles/s41467-023-36351-0](https://www.nature.com/articles/s41467-023-36351-0?ref=theegyptfiles.com)
- ScanPyramids ground-penetrating radar and ultrasound survey of the North Face Corridor: [https://www.sciencedirect.com/science/article/pii/S0963869523000245](https://www.sciencedirect.com/science/article/pii/S0963869523000245?ref=theegyptfiles.com)
- ScIDEP muon project at Khafre, *Journal of Applied Physics* 2025: [https://pubs.aip.org/aip/jap/article/138/4/044901/3355781/The-ScIDEP-muon-radiography-project-at-the](https://pubs.aip.org/aip/jap/article/138/4/044901/3355781/The-ScIDEP-muon-radiography-project-at-the?ref=theegyptfiles.com)
- ScIDEP conference abstract, Muographers 2026: [https://indico.wigner.hu/event/1727/contributions/4682/](https://indico.wigner.hu/event/1727/contributions/4682/?ref=theegyptfiles.com)
- SAR penetration in the Sahara (Shuttle Imaging Radar): [https://www.eoportal.org/other-space-activities/sir](https://www.eoportal.org/other-space-activities/sir?ref=theegyptfiles.com)
- SAR penetration by band in dry sand (review of studies): [https://www.sciencedirect.com/science/article/abs/pii/S0273117722002447](https://www.sciencedirect.com/science/article/abs/pii/S0273117722002447?ref=theegyptfiles.com)
- COSMO-SkyMed is an X-band system (ESA): [https://earth.esa.int/eogateway/missions/cosmo-skymed-second-generation](https://earth.esa.int/eogateway/missions/cosmo-skymed-second-generation?ref=theegyptfiles.com)
- The relieving chambers above the King's Chamber: [https://science.howstuffworks.com/engineering/structural/pyramid2.htm](https://science.howstuffworks.com/engineering/structural/pyramid2.htm?ref=theegyptfiles.com)
- Hawass's announced 30-metre passage, Jerusalem Post (methods): [https://www.jpost.com/archaeology/article-873314](https://www.jpost.com/archaeology/article-873314?ref=theegyptfiles.com)
- Hawass's 2026 announcement, Egypt Independent: [https://www.egyptindependent.com/egypt-to-announce-archaeological-surprise-in-2026-that-will-rewrite-history-zahi-hawass/](https://www.egyptindependent.com/egypt-to-announce-archaeological-surprise-in-2026-that-will-rewrite-history-zahi-hawass/?ref=theegyptfiles.com)

## Image credits

Images 3 to 5 are figures from Biondi & Malanga, *Remote Sensing* 2022, 14(20), 5231, published under CC BY and reproduced with attribution. The paper was retracted on 10 August 2026\. Images 1 and 2 are © Khafre Project, taken from the team's March 2025 press abstract and reproduced with credit for the purpose of criticism and review. The shaft render in image 1 is a higher-resolution copy of the same render printed in the abstract.