Poros is a small Greek

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

 island-pair in the southern part of the Saronic Gulf

Saronic Gulf

The Saronic Gulf or Gulf of Aegina in Greece forms part of the Aegean Sea and defines the eastern side of the isthmus of Corinth. It is the eastern terminus of the Corinth Canal, which cuts across the isthmus.-Geography:The gulf includes the islands of; Aegina, Salamis, and Poros along with...

, at a distance about 58 km (31 nautical miles) south from Piraeus

Piraeus

Piraeus is a city in the region of Attica, Greece. Piraeus is located within the Athens Urban Area, 12 km southwest from its city center , and lies along the east coast of the Saronic Gulf....

 and separated from the Peloponnese

Peloponnese

The Peloponnese, Peloponnesos or Peloponnesus , is a large peninsula , located in a region of southern Greece, forming the part of the country south of the Gulf of Corinth...

 by a 200-metre wide sea channel, with the town of Galatas on the mainland across the strait. Its surface is about 31 square kilometres (12 sq mi) and it has 4,117 inhabitants. The town of Poros has 4,102 of these inhabitants.