NR-1 Sinkhole NR-1 Sinkhole The NR-1 Sinkhole is a giant underwater sinkhole located in the Straits of Florida southwest of Key West, Florida. It is found at an approximate depth of of water at the foot of the Pourtales Escarpment, an area of Quaternary sediment. It was discovered in October 1994 during a survey conducted by the American submarine NR-1, a U.S. Navy nuclear research submarine, and is named for the submarine. It was first identified via side-scan sonar and near-bottom echo sounder data, prompting a second survey in May 1995 to confirm the finding. Discovery of the NR-1 Sinkhole prompted scientific
Devil's Sinkhole State Natural Area Devil's Sinkhole State Natural Area Devil's Sinkhole State Natural Area is a natural bat habitat near the city of Rocksprings in Edwards County in the U.S. state of Texas. Home to the Mexican free-tailed bat, access to the area is available only through advanced reservations. The Devil's Sinkhole is a vertical natural bat habitat. The opening drops down to reveal a cavern some below. The cavern was first discovered by local residents in 1876. H. S. Barber carved his name inside the cave in 1889. The area was transferred to the state of Texas in 1985, and open to the