Cave diver explores a Mexican sinkhole in an atmospheric photograph.

This claustrophobia-inducing image is taken from photographer Martin Broen's new book, "Light in the Underworld," which is a collection of shots from the Yucatán’s cenotes, or sinkholes.

The Yucatán peninsula in south-east Mexico is riddled with holes. A giant asteroid struck Earth 66 million years ago near what is now the town of Chicxulub, creating a massive depression and causing fracturing of the porous limestone bedrock. Over millions of years, rainwater dissolved the stone, creating underground rivers, caves, and cenotes (sinkholes).

Photographer Martin Broen has explored 280 of the Yucatán’s cenotes. Atmospheric shots of these cenotes are collected in his book, "Light in the Underworld," which is out now in the US and will be released on 17 September in the UK. This image, taken in 2020, shows the cave area of a cenote called Chan Aktun Ha (a Mayan name meaning “little water cave”) in the state of Quintana Roo. Here, a cave diver is exploring among pristine stalactites and stalagmites.

During rain showers in the Mexican jungle, water washes tannin from the vegetation into the cenotes, creating a tannic acid solution,” says Broen. “These natural filters provide a surreal green, yellow, or red atmosphere to the caverns."

The shallow caves of the Yucatán Peninsula have been flooded for the past 8000 years. “The more I dive, the more I discover the beauty and secrets of these caves, uncovering unique fossils of extinct megafauna, indications of the first Palaeo-Americans, and Mayan artifacts,” says Broen.