Poros (Greek: Πόρος) is a green Greek island close to Peloponnese by a 200 m (656 ft) wide sea channel, with the town of Galatas on the mainland across the strait. Its surface area is about 31 square kilometres (12 sq mi) and it has 3,780 inhabitants. The ancient name of Poros was Pogon. Like other ports in the Athens islands, it is a popular weekend destination for Athenian travellers.
Poros consists of two islands: Sphairia (Greek: Σφαιρία, pronounced [sfeˈria]), the southern part, which is of volcanic origin, where today's city is located, and Kalaureia (Greek: Καλαυρία, [kalavˈria]), also Kalavria or Calauria (meaning 'gentle breeze'), the northern and largest part. A bridge connects the two islands over a narrow strait.
Poros is an island with rich vegetation. Much of the northern and far eastern/western sides of the island are bushy, whereas large areas of old pine forest are found in the south and center of the island. It has a good road network and adequate tourist infrastructure, which makes it a popular resort for short holidays.