The Cayos Arcas is a chain of three tiny sand cays and an accompanying reef system in the Gulf of Mexico, 128 kilometres (80 miles) from the mainland.

The main island is Cayo del Centro, with an area of 13.7 hectares (33.9 acres), which is scantily covered with grass.

On the island, viewed through Google Maps, along with a covering of Palythoa caribaeorum, Zoanthus sociatus, Acropora palmata, Montastraea annularis, and Diploria strigosa, appear to be a few small buildings and small signs of past human habitation.

To the west, the island has a fairly long spit of sand leading to a sort of tidal lagoon.

Further to the north of this island is another shallow reef that, although not breaking the surface, is about 230 feet (70 metres) wide and less than 20-foot (6.1-metre) deep.

During the American Civil War, the famous Confederate raider CSS Alabama used the remote chain as a rendezvous point to be resupplied while conducting operations in the gulf.