The three islands are similar, but not identical, in their landforms. Grand Cayman is irregularly shaped and includes the North Sound, a shallow bay of about 35 square miles. The elevation is low (about 60 feet above sea level at its highest point).

The Sister Islands are each amoeba-shaped and small. Cayman Brac, about 12 miles long and a little over a mile wide, rises highest. The Bluff, from which the island gets its name (Brac is Gaelic for bluff), soars to a nosebleed level - by Caymanian standards - of 140 feet above sea level. This cliff falls into the sea and is one of the most picturesque features of the islands. A few miles west, Little Cayman is the flattest of the three islands, reaching just 40 feet above sea level in the middle of the island.

These three islands are the peaks of a submerged mountain range, Cayman Ridge, part of a chain running from Cuba to near Belize. The islands are actually limestone outcroppings with little soil, so vegetation is not as lush as that found on other Caribbean islands.

Two types of limestone form most of the surface: bluff limestone, formed about 30 million years ago, and ironshore, a substance created about 120,000 years ago, combining limestone with coral, mollusk shell, and marl. Ironshore accounts for the pocked surface that holds little pockets of soil (and makes walking barefoot just about impossible) on much of the islands.

The limestone is very porous, so most rain is quickly absorbed and the islands have no rivers or streams. That means little runoff and therefore greater clarity in the surrounding waters. Divers rave about the visibility, often 100 to 150 feet. Beyond the reaches of land, each island is surrounded by coral reefs, producing some of the best snorkeling and scuba diving in the Caribbean.

Divers have a chance at spotting a wide array of marine life, partly because of the deep water located nearby. The Cayman Trough, the deepest water in the Caribbean, lies between this nation and Jamaica, with depths that plunge over four miles into inky blackness.

NOTE: All beaches in the Cayman Islands are public.