It is located on the south side of Kastellorizo; you can visit it by boat and it is known as Azure Grotto, cave of Parastas, or Fokiali (from the ‘fokies’ that live inside). It is considered one of the biggest and most beautiful underwater caves in Greece and it is famous worldwide for its rich stalactite decoration. It was created during the Pleistocene because of the limestones’ karstic erosion of Upper Cretaceous-Eocene age covering most of the island. Its dome rises at 25m and is covered by colorful stalactites which are lighted by the reflections of the solar rays. Its length is 155m. The natural beauty that the refraction and the reflection of the solar rays create leaves the visitors speechless. The second chamber of the cave has a gravel section that constitutes a hideaway for the Mediterranean monk seal Μonachus monachus. The entrance of the Azure Grotto barely fits a small boat in its height when the waters are calm.