Thassopoula is an uninhabited islet with low vegetation in the Aegean Sea. It is located between the island of Thassos and the coastal area of the regional unit of Kavala, across the delta of the river Nestos. It is considered the smallest islet in northern Aegean; there are three beautiful beaches on it.  Colonies of gulls, cormorants, and herons are featured on the islet.

Every year, there is an open sea swimming competition from Keramoti to Thassopoula.