Lake Bacalar

Lake Bacalar, on the southern edge of Mexico's Yucatán Peninsula near the border with Belize, is a long, narrow ribbon of fresh water, more than 50 km from north to south and barely two kilometres across at its widest. It is often called the "lagoon of seven colours", and the name is earned: over its pale limestone bed the water shifts from almost white along the shallows through turquoise and cobalt to near black where the bottom drops away into sunken cenotes. The deepest of these, the Cenote Negro, reaches about 55 metres. It is one of the few large surface lakes on a peninsula where porous limestone swallows almost all the rain, and it is fed from below by underground rivers.

The lake's real rarity lies in the shallows. Along its shores grow stromatolites, rounded, cauliflower-like mounds built up layer by layer by microbial mats that trap and cement lime. Structures of this kind are among the oldest evidence of life on Earth and survive today in only a handful of places; the Bacalar colonies, dated to between six and ten thousand years old, are considered the largest freshwater stromatolite system in the world. They are also fragile, and some stretches of shore are now protected because the mounds have been declining under the pressure of growing tourism and wastewater.

The town of Bacalar on the western shore gave the lake its name, from the Maya Bakhalal, usually rendered as "surrounded by reeds". It is counted as the oldest settlement in Quintana Roo. The Spanish refounded it and, in 1733, completed the Fort of San Felipe to guard it against English pirates and, later, Maya rebels; the star-shaped fort now houses a small museum of piracy, and its ramparts give one of the best views over the water. A channel known as the Canal de los Piratas links the lake to the network of lagoons, streams and the Río Hondo that runs out to Chetumal Bay, the route those raiders once used. At its southern end, at Los Rápidos, the water runs fast and shallow over more stromatolite beds.

Getting there

The town of Bacalar lies on the western shore, about 35 km north of Chetumal, the state capital; the lake as a whole is some 25 km from the city. The nearest airport is Chetumal International Airport (CTM), about 27 km away. The fort, the town waterfront and several cenotes along the shore can be reached on foot or by short drives from the town.