A new expedition to explore the Mayan complex at Chichen Itza has been launched, that will include studying the 1,000-year-old Temple of Kukulkan, and the landscape’s numerous sinkholes. The expedition’s aim is an attempt to uncover the secrets of a mysterious underworld that is supposed to exist there according to Mayan oral history. This is the first comprehensive exploration of the site in roughly half a century.

"Something on this scale has never been attempted, but we’re confident that it will help us understand this site in a way that wasn’t possible before," explains National Institute of Anthropology and History archaeologist Guillermo de Anda. De Anda is also the director of the Great Maya Aquifer Project. "With this data, I believe we will conclusively find out if the local legends of an elaborate underworld are true."

The expedition is making use of modified ground-penetrating radar equipment to look for hidden chambers and passageways within the ancient Mayan step pyramid, nicknamed "El Castillo", and will also be used to search the surrounding landscape as well. Kayak-mounted sonar equipment will be used to map the flooded sinkholes found in the region, called cenotes, to determine if they are the entrances to a subterranean network spoken of in Mayan legend. These legends describe this underworld as the realm of the gods.

The team will also use laser-scanning and photogrammetry equipment to produce finely-detailed 3D maps of the caverns. "In the end, we’ll be able to combine data from these imaging tools and produce a millimetre-scale, 3D ‘super map’ of the entire site, above and below the ground," says Corey Jaskolski, an engineer with National Geographic. The team has already found new caverns, both submerged and dry, and "a number of anomalies" behind the temple’s walls and under the floor of the inner chamber’s Red Jaguar throne.