The Marieta Islands were originally formed many countless years ago by volcanic activity, and are entirely uninhabited. The isles are about an hour long boat ride west-northwest from the shore of Puerto Vallarta and are seen daily by hundreds of vacationers, yet nobody could legally set foot on the isles. In the very early 1900s the Mexican army conducted bomb testing on the islands since nobody lived there. A lot of blasts and large surges happened on the isles creating incredible caves and rock formations . After a huge global protest, started by researcher Jacques Cousteau in the late 1960s, the federal government chose to classify the isles a national park and therefore protected it against any sort of fishing, scouting or human activity.