Located a short 37 miles off the Greek mainland, Hydra is a favorite getaway for Athenians. Visitors are its main industry, whether from the neighborhood or around the world. Motor vehicles are banned, and local transport takes the form of water-taxis and donkeys. But most people walk around compact Hydra town, patronizing the shops and cafes along the waterfront crescent. On the streets leading up from there, mansions that once belonged to powerful shipping captains are stuffed with period furniture.