Vieques Island Bunkers, Puerto Rico
In 1941, the American Navy overtook the small Puerto Rican island of Vieques and built a series of secret concrete bunkers that stored ammunition during World War II. The Vieques Bunkers also became a testing ground for weapons, since hills completely obscured the structure.
By 2003, residents had become irritated by the constant military occupation and repeated protests forced the Army to withdraw from Vieques, leaving the bunkers untouched ever since.