Piperi is an 8 km2 large island in the group of the Sporades. It is situated northeast of Alonissos island and its highest point is 352 m. The island is part of a protected National Marine Park and fishing is prohibited in a 3 miles distance. Piperi is the home of the protected mediterranean Monk Seal and rare species of birds of prey. Piperi is an inaccessible and rocky island that cannot be visited or even approached if you do not have special permission. On the island grow pine trees and there are rare species of plants.

Only research teams with a specific licence are allowed to approach the island of Piperi. The National Marine Park was founded in 1983 for the protection of the Monk Seal and large parts of the islands and the waters east and north of Alonissos are now prohibited for visitors.