Across the coast of Keri , lies the island of Marathonisi, that imposingly jewels the gulf of Laganas. The island has two reefs, called Pontikonisia, that in the old times were linked to the cape of Marathias. The nature there is pure exotic as the island has no inhabitants.
In the north-west of the island, tall bluffs are raised. In the long gold sandy beach that unfolds like a tongue in the sea, the turtles Caretta-Caretta make their nests.