Greece is characterized by an extremely fragmented, rugged landscape hosting a great diversity of ecosystems and an outstanding biodiversity. Almost 5% of its extensive coastline consists of ecologically sensitivewetlands. Two thirds of the total population live no further than 2 km from the coast and most of the important urban centers are coastal, while almost all of the tourist infrastructure is divided among islands and the coastal mainland.
Greece's climate is divided into three classes: A Mediterranean climate features mild, wet winters and hot, dry summers. Temperatures rarely reach extremes, although snowfalls do occur occasionally even in Athens, Cyclades or Crete during the winter. An alpine climate is found primarily in Western Greece (Epirus, Central Greece, Thessaly, Western Macedonia as well as central parts of the Peloponnese like Achaea, Arkadia and parts of Lakonia where the Alpine range pass by). A temperate climate is found in Central and Eastern Macedonia as well as in Thrace at places like Komotini, Xanthi and northern Evros; with cold, damp winters and hot, dry summers.
Each national park consists of a core and the area surrounding it. According to Greek Law the core cannot be smaller than 15,000,000 square metres (5.8 sq mi), with the exception of marine national parks. The surrounding area must be larger than, or at least equal to, the size of the core.
In the core of the national park, only scientific research, mild recreational activities, and the acquiring of environment related information are permitted. The creation of menageries, fish farms, the building of roads, outposts, camping and hiking infrastructures, along with woodcutting infrastructures and pastures are permitted in the surrounding area of the national park.
