The island of Marathonisi or Turtle island is placed across Limni Keri, in Laganas bay. It is not a single island but also includes two more small islets called Pontikonisia. Its perimeter is just about a mile and can be reached by boat from Limni Keri or Laganas.
Visitors must be very careful during their trip to Marathonisi because this is a breeding place for the sea turtles Caretta Caretta. This is why visitors are absolutely not allowed to explore the island, but they are expected to stay only in the first 5 meters of the beach so that they do not harm the nests of the sea turtles, that is why Marathonisi is included as part of Zakynthos Marine Park. Moreover, another species in danger of extinction, the Monachus Monachus sea seal goes there to rest and reproduce.
Marathonisi is not inhabited and keeps its characteristic pine, olive and green oak forests in excellent conditions. It has thick vegetation everywhere and two wonderful beaches, one with pebbles and the other with white sand. The first is ideal for snorkeling and exploration since on its right there are two large sea caves in which small boats can enter. Small sandy beaches are formed between the caves, dreamy for swimming. The sandy beach is located in the front part of the island, overlooking the beach of Laganas. A tongue of sand penetrates the sea and is ideal for relaxation, sunbathing and swimming. The islet of Marathonisi is totally unspoiled. There are no tourist facilities on the island therefore take care to carry with you water and other supplies. Mooring and overnight stay on the island is prohibited.