In 2011, he took a leading part in the controversial geological survey of the archeological site at
Gunung Padang as chief geologist of the government-sponsored (TTRM, 'Integrated and Independent Research Team'). Natawidjaja's conclusions gained the attention of Indonesia's President
Susilo Bambang Yudhoyono, who set up a task force. An archaeologist who did not wish to be named due to the involvement of the country's president, stated: In October 2023, an article by Natawidjaja et al., published in
Archaeological Prospection, claimed that Gunung Padang is the oldest pyramid in the world, dating as far back as 27,000 years ago. In March of 2024, the publisher of
Archaeological Prospection,
Wiley, and the editors, retracted that paper stating that:...the radiocarbon dating was applied to soil samples that were not associated with any artifacts or features that could be reliably interpreted as anthropogenic or “man-made.” Therefore, the interpretation that the site is an ancient pyramid built 9000 or more years ago is incorrect, and the article must be retracted.In 2023 he claimed to have discovered a 75,000 year old pyramid in
Lake Toba, north Sumatra. The Indonesian Geological Agency expressed doubts about the claim, suggesting that it may be one of the triangular facets found on the hills of the lake that formed after the caldera was formed and then used by later civilizations. ==Awards==