"Hell" is a group of short, black, limestone formations eroded from ironshore in Grand Cayman. Located in West Bay, it is roughly the size of half a football field. Visitors are not permitted to walk on the limestone formations but viewing platforms are provided.
There are numerous versions of how Hell received its name, but they are generally variations on "a ministration exclaimed, 'This is what Hell must look like.'"
It is also claimed that the name "Hell" is derived from the fact that if a pebble is thrown out into the formation, it echoes among the limestone peaks and valleys and sounds as if the pebble is falling all the way down to "Hell." Regardless of how it first came to be called Hell, the name stuck and the area has become a tourist attraction,
Marine Life - Definitives