Hydra (Greek: Ύδρα, pronounced [ˈiðra] in modern Greek) is one of the Saronic Islands of Greece, located in the Aegean Sea between the Saronic Gulf and the Argolic Gulf. It is separated from the Peloponnese by narrow strip of water. In ancient times, the island was known as Hydrea (Υδρέα, derived from the Greek word for "water"), which was a reference to the springs on the island.
The municipality Hydra consists of the islands Hydra (area 50 km2), Dokos (pop. 13, area 12.5 km2) and a few uninhabited islets.
There is one main town, known simply as "Hydra port" (pop. 2,526 in 2001). It consists of a crescent-shaped harbor, around which is centered a strand of restaurants, shops, markets, and galleries that cater to tourists and locals (Hydriots). Steep stone streets lead up and outwards from the harbor area. Most of the local residences, as well as the hostelries on the island are located on these streets. Other small villages or hamlets on the island include Mandraki (pop. 33), Kamini, Vlychos (28), Palamidas (18), Episkopi, and Molos.
Hydra depends upon tourism and Athenians comprise a sizeable segment of its visitors. High speed hydrofoils and catamarans from Piraeus, some 37 nautical miles away, serve Hydra, as do daily island ferry boats. (The ferries take about three hours for the transit; the hydrofoils and catamarans substantially less.) The island also has ferries to Aegina, Poros, Spetses, Nafplion and Monemvasia.
Garbage trucks are the only motor vehicles on the island, as cars or motorcycles are not allowed by law. Donkeys, bicycles, and water taxis provide public transportation. The inhabited area, however, is so compact that most people walk everywhere.
Hydra benefits from numerous bays and natural harbours, and has a strong maritime culture. The island remains a popular yachting destination, and is the home of the Kamini Yacht Club, an international yacht club based in the port of Kamini.