Poros is a small Greek island in the Saronic Gulf, separated from the Peloponnese coast by a narrow channel just 200 metres wide. The town climbs steeply up a volcanic hill — blue-domed clock tower, neoclassical houses, and a lively waterfront with fishing boats and ferries. It is close enough to Athens (two hours by ferry) to be reached easily as a day trip, though it rewards a longer stay.
The island splits into two parts: the northern half is mostly pine forest and the site of an ancient sanctuary of Poseidon; the southern half (where the town sits) is rockier and more developed. The beaches are modest by Greek standards, but the atmosphere in town — especially in the evenings — is relaxed and genuinely Greek rather than tourist-packaged.