Divers preparing for their dive in the Grotto, a collapsed cave, Saipan, Northern Mariana Islands
Michael Runkel/imageBROKER/© Michael Runkel/imageBROKER
The Grotto is a famous and impressive underwater limestone cavern that reaches some 21 meters (70 feet) below the sea at its deepest point. Considered one of the best cavern-dive spots in the world, its wealth of underwater life—including turtles, parrotfish, many hard and soft corals and colorful nudibranchs—makes it hugely popular with snorkelers and swimmers, too. Note that navigating the steep 112 steps down to the cave requires a certain level of physical fitness.