At the same time it constitutes a municipality (Greek δήμος, Dimos ) in the Attica Regional District islands.
The island of Poros is removed by a 300 meter wide channel from the Peloponnesian coast near the town of Galatas. The larger northern part of the island Kalavria ( Καλαυρία ) is is an isthmus ( isthmus ) with the smaller southern Sferia ( Σφαιρία ) of volcanic origin, connected. Characteristic of the southern part and comb the island is a dense growth of Aleppo pine that reaches down to the coast. The island is just over 31 square kilometers and has about 4,000 residents, which focus on the main town of Poros. This extends from the west side of Sferia up across the Isthmus.
In the north and north-east of olive and citrus trees are grown and operated fish farming on the plateau fousas thrives wine. In addition, the tourist infrastructure is well developed.
Sferia is of volcanic origin and is one of the ( geologically considered to be active) volcanoes of the Saronic Gulf ( Aegina, Methana and Krommyonia ). Geology is the volcano of Poros on the ditch of Epidaurus, a tectonically highly stressed zone, extending from south to north on the east coast of the Peloponnese. The strait between Galatas and Poros is one of them and has lowered since ancient times. Pausanias tells us that he was still wading through the swamp, which lay between the two places and is now up to four meters deep in the sea. Subsidence and uplift go further and future volcanic eruptions are to be expected especially in the region around Methana.
On Poros many old houses are preserved, giving also the capital of its picturesque appearance. The island is a destination for Athenians and easily accessible by the regular ferries and hydrofoils from Piraeus.
Worth seeing is the small archaeological museum on the island, which is stocked with finds from the ancient Troizen, from the Mycenaean Acropolis at Galatas and finds from the Mycenaean sanctuary of Methana. The ancient name of Poros was Pogon (Greek ΠΟΓΟΝ ). Recently, spoken among experts believe that this could have found the grave of the mythical hero Theseus at Galatas on the hill Magoula.
On Kalavria are the foundations of a temple of Poseidon. On Kalavria the monastery Zoodohos Pigis is (ie life-giving source).
Clock tower on Poros
Monastery Zoodochos Pigis