Astypalaia is the westernmost island of the Dodecanese located 117NM away from Piraeus, 96NM away from Rhodes and 23NM away from Kos.
The island is actually divided in two parts, the eastern one (called Mesa Nisi) and the western one (called Exo Nisi) that are connected by a narrow strip of land called Steno.
The islets of Agia Kyriaki, Hondro, Ligno, Kounoupi and Koutsomytis lie to its southeast, while the islets of Ofisoussa, Htenia and Pontikoussa lie to its west.
The island extends over an area of ​​96.4 km² and the summit of Vardia (at 482 m) is its highest peak.
Its coastline with a total length of 124 km consists of many small and mostly steep beaches that are scattered all around the island.
Astropalia is the capital of the island located at the southern coast of Exo Nisi. There are three other villages, Livadi, Maltezana (or Analipsi) and Vathi.

Astypalaia’s terrain ranges from hilly to mountainous.
Garrigue and shrubs extending over large areas are the most common types of vegetation on the island. Intermittently flowing torrents form valleys where fruit trees, especially citrus and olive trees, grow.
Important colonies of seabirds, seals (monachus monachus) and endemic chasmophytes exist on Astypalaia and its surrounding islets. The region’s avifauna includes the species of Rufinus, Artemis, Eleonora’s Falcon and Phalacrocorax Aristotelis.
The Posidonia meadows, the habitats of the continental shelf’s bedrock and of the shallow bays of Astypalaia are the most representative of the Aegean Sea and possibly of the whole southeastern Mediterranean region.
The eastern side of the island, along with the surrounding islets and the sea area around them, are protected by the European network NATURA 2000. The entire island is very important for the Greek avifauna.