Due to its special flora and fauna, a large part of the natural environment of Chania consists of protected areas for hunting, national parks and natural habitats (lake of Ayia, lake of Kournas, islands of Gavdos and Gavdopoula, Elafonissi, etc.) which are protected by “Natura 2000”. Protected species, such as the Cretan goat and the vulture-eagle, live at the National Park of the gorge of Samaria and there is of endemic plants which grow only there. The grandest gorge in Europe, the Samaria gorge, starts at the tableland of Omalos and is 16 km long and from 3 to 300 m wide. Crossing of the gorge, which lasts about 4 to 5 hours, is allowed from May to September. For wanderers, mountain climbers and cave explorers, there are many well-loved destinations in the county of Chania, such as the gorge of St. Irene in Selino, Imbros in Sfakia, Aradaina, Therisso etc. and more than 1500 caves and sea caves. The most interesting ones are those of Apokoronas (Samonas, Kournas, Melidoni etc.), of St. John and the Bearcave near the convent of Gouverneto.