Built for the most part in the late 18C, the ship-owners' houses (archontika) on the island of Hydra are testament to the power of their owners. The high stone walls with narrow barred windows lend them the appearance of fortresses, but hide gardens planted with rare flowers, loggias inspired by Genovese architecture, vast rooms with marble floors and painted ceilings. Don't miss the residences of Lazaros Koundouriotis and his brother, Giorgios, today turned into museums.