Guantánamo Bay is a bay in Guantánamo Province at the southeastern end of Cuba. It is the largest harbor on the south side of the island and it is surrounded by steep hills which create an enclave that is cut off from its immediate hinterland.

A harbor, or harbour, is a sheltered body of water where ships, boats, and barges can be moored. The term harbor is often used interchangeably with port, which is a man-made facility built for loading and unloading vessels and dropping off and picking up passengers. Harbors usually include one or more ports. Alexandria Port in Egypt is an example of a harbor with two ports.