Known variously as Hydra, Ydra, and Idhra, this island is one of the most fashionable in Greece. It has long been a haven for artists who are attracted by the clear light and lively atmosphere of the harbor. In the 18th-century, the isle was home to fabulously rich sea captains who sailed as far afield as America. Today their stately, Italian-style mansions and villas have been restored to their former grandeur. Be prepared to walk a bit on Hydra, as no cars are allowed here.