The area extends over three prefectures: Viotia, Fthiotida and Fokida. It includes the National Park of Parnassos, one section being in Viotia and the rest in Fokida, the northeastern border of the mountain and the Aesthetic Forest of Tithoreas which belongs to Fthiotida. Of great archaeological importance is the Oracle of Delphi which is also included in the area. The predominant climate is continental with a relative cool but dry summer, rainy in the autumn and a heavy winter which also last many months.
The greatest percentage of rainfall is observed in November whereas the driest month is August. The average annual rainfall is about 1,000 mm. There is a high frequency of hailstorms which cause damage to the cultivation and the reared animals. For at least two months out of the year the tall peaks of Parnassos and the National Park are covered with snow which could reach up to four meters above ground. In the alpine zone the snow continues to melt up until June. The substratum of the area consists of limestone settlements of various ages.
The National Park of Parnassos has a main section the size of 3,513 hectares (about 20% of the area) and this does not include the highest peaks of the mountain (i.e. Liakoura, Gerontovracho) although which have been included in the area. Beginning from the lowest altitude of the area (500 m) and reaching up to 800 m, it is observed that the evergreen broadleaf trees are predominant. As the altitude increases a transition towards coniferous trees can be observed. A few Pinus nigra ssp. pallasiana clones can also be observed. From an ecological point of view many types of vegetation are preserved with an excellent structure among which some are also types of priority natural habitats.
There are alpine valleys at high altitudes, bare cliffs and moraines, impressive woodlands, mainly oak tree and endemic fir forests. The above features, in combination with its geomorphology of interest render the area especially rich in flora and fauna. The National Park of Parnassos was founded in 1938. It was the second Greek National Park after that of Olympus.
Its main area is under the Conservation Zone (ZEP) according to Directive 79/409/EOK for birds. Also, the world reknown Oracle of Delphi has been included in the suggested area, not only due to its archaeological importance but also since it has been studied extensively as to the species of plants and animals found there and includes some of the most important species reported in Greece.
The preservation and conservation of Delphi is advised also as a natural reserve not only for the preservation of its significant flora and fauna but also for its ecotouristic appeal. The entire area is important in regards to its birds of prey, woodpeckers and other birds.