Poseidium (Karpathos)

Poseidium or Poseidion (Ποσείδιον), also known as Potidaeum or Potidaion or Karpathou Ktoina, was a town of ancient Greece on the island of Karpathos, and served as the harbour of Karpathos.

Its site is located near modern Pigadia i.e. Karpathos Town.