A narrow sea strait separates the island from Galatas, on the opposite coast of Peloponnese. According to the mythology, Theseus was born, on this lush island.
In the seventh century BC, Poros, whose name was Calauria the ancient league of seven cities. During the Revolution of 1821, its inhabitants joined forces with those of Spetses and Idra to put their boats in the service of the resistance. The charming town of Poros is named the capital and also the port of island. East of the port lies the green island of Bourtzi with a small castle built in 1827. Archaeological Museum of Poros, have kept important finds from the island. At a distance of about 5 km north-east of the town, there are traces of the sanctuary of Poseidon, in Doric style, of the sixth century. B.C. The area is called by the islanders Palatia and has an exceptional view.
Near the port, on the southern coast of the island, lies the charming Askeli with a wonderful sea and the dense pine forest. On a hill near the beach, lies the monastery of Zoodochos Spring Kalavrias.
About 3 km northwest of Poros, are Mikro and Megalo Neorio, beautiful sandy beaches, where pine trees reaching to the limpid sea. From Poros, you can make excursions to the nearby coasts of Argolida. Exactly opposite the port of Poros, on the coast of Peloponnese, is the verdant village of Galatas with idyllic South Lemonodasos (lemon wood). In the port of Poros operates a filling station for water and fuel for boats.