The second most important town of the island, it is located NE of Eressos, N of Plomari and NW of Mytilene.
The town (pop. 1,497 at 2001 census) is on the northern part of the island, just some 6 km north of the popular beach town of Petra. One of the most noticeable features of the town is the old Genoese fortress on the hill in the middle of the town.
The municipal unit of Míthymna stretches eastward from the town along the northern part of the island; it is the island's smallest municipal unit in land area at 50.166 km². Its population was 2,433 at the 2001 census. The next largest towns in the municipal unit are Árgennos