Sometimes called Νησια Αιγαιου (Nissia Aegeou - East Aegean Islands), sometimes North Aegean Islands or Northeastern Aegean Islands, this are all the islands in the Aegean Sea which do not belong to the Sporades, Cyclades, and Dodecanese Islands. This are mostly numerous islands close to the Turkish coast (actually an ongoing point of dispute between the two countries) and some islands at the northern coast of the Aegean.
The islands are mostly composed of limestone, and many of them are karstified, so there is a huge amount of caves to be found. However, only a few are open to the public.
More than 67 caves have been discovered on Samos, most of them are situated at the west part on mountain Kerki. The most famous are the cave of Kakoperato near the village Kosmadei, the cave of Panagia Makrini, the cave of Aghia Triada near the village Kallithea, and the cave of Pythagora in which, according to legend, Pythagoras found refuge when he was persecuted by Polycrates, the tyrant of Samos.
The island of Lesvos has about 200 caves, the longest is Magaras or Megara Cave near Alifanta with a length of 120 m. The second longest is Agios Ioannis Cave which is also called Fousa Cave near Mychos with a length of 90 m. The cave of Agios Vartholomeos in Taxiarches is about 60 m long. It had some impressive stalactites but most of them were destroyed by visitors. Prehistoric vessels discovered discovered in the cave are now on display at the Archaeological Museum of Mytilene. The island has a UNESCO Global Geopark, highlights are the Petrified Forest and the Museum of Natural History in Sigri village.