Watch those stalagmites!

The luminescent Caribbean Sea is not the only beautiful water on the Yucatán coast. Tucked into the scrub jungle along the Mayan Riviera is a network of limestone sinkholes, known as cenotes (pronounced say-no-tayes). which open to clear, fresh water that laps against glistening stalactites and stalagmites. The cave openings contain cool shallow water that courses through labyrinthine tunnels, mostly underground.

But the cenotes, which have long been a favorite with tourists from home and abroad, are suffering for their popularity.

The mythical reputation of the cenotes as the gateway to the secret Mayan underworld makes them popular with divers, snorkellers and swimmers. Visitors enjoy exploring the depths from which jade, gold and human remains have been dredged – remnants of Mayan sacrifices. But as they plunge into the cave depths – the bottom of some have never been reached – they can snap off the delicate rock formations with their fins and heavy flashlights. The stalagmites and stalactites grow a mere one centimeter every five years and are irreplaceable.

There are other problems, according to Dave Tomlinson, owner of the Cenote Dive Center in Tulum and Playa del Carmen. The water is being degraded by swimmers entering the caves wearing sunscreen and insect repellent to keep off the clouds of mosquitoes that thrive in such dark, moist conditions.

“We try to avoid having people go into the cenotes with wearing sunscreen and insect repellent. There are lots of signs up,” says Tomlinson.

“But everyone uses sunscreen, so it’s tough.”

The degradation of the cenotes goes beyond the direct impact that visitors have on the underwater caves. There is a larger problem emerging along the Mayan Riviera as more and more hotels spring up to accommodate the tourists flocking to the coast. As I showered in one of Tulum’s pretty beach hotels, I noticed that the water coming out of the shower was sweet – why is that?

“It’s because many of the hotels along the coast draw their water from the cenotes themselves,” says Lucy Gallagher, one of the three directors of the NGO Mexiconservación. Ironically, it’s becoming more and more common for these guest houses to call themselves “eco-hotels”.

“The term ‘eco’ has become really fashionable because being environmentally friendly is a new trend. A lot of people are now concerned about the environment when they go on holiday and are looking for more environmentally friendly initiatives.

“However the term ‘eco’ has been taken on as a bit of a buzzword and very often a lot of the ‘eco-hotels’ and ‘eco-tours’ may not be so. We encourage people to enquire about the environmental policies of hotels, restaurants and tours they go on,” advises Gallagher.

The problems on the coast aren’t just affecting the cenotes. The beach of the nearby UNESCO Sian Ka'an Biosphere is covered with junk and litter, and activities such as turtle tours – where tourists are given the chance to release baby turtles back into the sea from the beach – draw travelers, but can wreak havoc on the animals’ natural cycles.

The moral of the story: if you want to be eco-friendly, you will have to do more than look for the word. Ask questions before you sign up for tours or hotels down on the Caribbean Coast.