Marathonisi (Turtle Island)

An island uninhabited except for the sea turtles, Marathonisi (Turtle Island) is part of the National Marine Park of Zakynthos, which strives to protect sea turtles and their habitats. You’ll discover two beaches on the island–one sandy and one rocky. Book a boat tour to visit the island, or rent a motorboat to reach the island on your own. Even if the turtles aren’t there when you visit, look for their tracks in the sand. If you stop at the sea caves on the other side of the island, you can snorkel and search for more sea turtles.
Source : inspirock.com 
https://www.youtube.com/watch?v=VkNHlID8mLo
https://www.youtube.com/watch?v=Otvtc0Zbu2A