Schiza is the biggest island in the Oinousses cluster, with an area of 12 square kilometres. Historically, it was known as Kamprera or Kavrera, and it appears to have been inhabited mainly during the Roman era, as evidenced by findings and traces of a settlement. Since then it was occasionally used by fishermen for mooring, while in 2001 it only had 2 permanent residents. Schiza is included in the Natura 2000 Network, together with the nearby Sapientza.
The most important attraction of the island is a cave with stalactites and stalagmites, which is called “Mavri Troupa” (Black Hole), due to the tradition, according to which it was a hideout for pirates, but also because of its mysterious and imposing ambiance. Even though it can be visited, this cave has not yet been explored and this means that the “treasures” it might hide still remain well stashed.