Mexico’s fragile Lagoon of Seven Colors is threatened by development

We also saw a firsthand illustration of not-so-conscious tourism. We paid a visit to the Rapids, one of the greatest collections of stromatolites in the world, according to researchers at the University of Wisconsin, who have been studying these formations for a decade. Here, scores of swimmers ignore the warnings each day and clamber all over the fragile formations, some of which are believed to be up to 9,000 years old.