The lake that contains the oldest form of life on Earth, 3 billion years old

Lake Bacalar, Mexico

Credit, Pola Damonte/Getty Images

The beauty of Lake Bacalar, according to Claudio Del Valle, goes beyond the seven brilliant shades of blue, which range from the vivid turquoise to the deep cobalt, of the Mexican lagoon.

In fact, says the local tour guide, it goes up to 100 m deep — in the limestone bottom of the lake, which is home to the oldest life on the planet.

Del Valle explains that the most important thing when visiting the long, narrow lake near the border with Belize is to leave no traces.

He spent years taking groups on pre-dawn stand-up paddle tours as the sun cast its first rays over the lagoon.