Islas Marietas are a group of inhabited islands off the coast of Nayarit. In the early 1900s, the Mexican government began conducting military testing on the islands since they were uninhabited. Many bombings and large explosions took place on the islands causing caves and rock formations to be created. After a massive international outcry, started by scientist Jacques Cousteau in the late 1960s, the government eventually decided to declare the islands a national park and therefore protected against any fishing, hunting or human activity. The Islands are absolutely breathtaking and have a very famous hidden beach which can be entered by snokelling into it. There is a lot of flora and fauna to explore by scuba diving or snorkelling.