The island of Nisyros is situated in the south-eastern Aegean (longitude 36°35’ north, latitude 27°10’ east) in the Dodecanese group of islands.
It covers an area of 41.2 square kilometers and reaches a height of 698 metres. It is surrounded by 5 other tiny islands, the largest of which is Yali, followed by Pyrgousa (or Pergousa), Pahia, Strongyli and Kandeleousa (or Fanari).