Hydra is small, and most of the pleasure of being here is walking — up the stone staircases between the captains' mansions, along the rocky coast paths to swimming spots, or out to one of the hilltop monasteries. The town's museums and waterfront landmarks can be seen in a morning; what holds you on the island is the rhythm.
If you only do one walk, make it the climb to the Monastery of Profitis Ilias above the town — an hour or so on a stony donkey path, with the harbour falling away below you. For swimming, walk west along the coast road to Vlychos or further to Bisti, where the water is cleaner than at the town beaches.