The National Park of Ordesa was created in 1918 by royal decree. Today, the park is 16,000 hectares big and includes lush valley forests, meadows, steep limestone slopes and delicate alpine reaches. Located in the Aragon Pyrenees near the National Park of the French Pyrenees, the Ordesa National Park constitutes a perfectly preserved natural enclave.
The park of Ordesa is divided into three separate valleys coming from the Monte Perdido, "the lost mountain." The main valley shelters 171 species of birds. The park is especially notable for sheltering the only herds of Pyrenees mountain goats in existence and a healthy number of chamois deer, which in the nineteenth century were in danger of becoming extinct.

Activities:
One of the great advantages of Ordesa is that it offers a variety of hiking opportunities, from the relatively short and easy to the very challenging. Your best bet is to land in the almost-too-charming village of Torla, frequently overran by tourists.
The most popular walk is the Circa Soasa, which takes 5 to 8 hours and offers a lot of beauty and interest without a lot of exertion.
Climbers have many choices. Two noteworthy are the Petit Vignemale, which reportedly offers almost every possible technical challenge, and for very experienced climbers, the Aqisclo Valley.
Times to Visit:
The park is open from May through mid-November, but if you plan to visit early or late in the season, double-check snow conditions. Also, mid-July through August is the height of the Spanish vacation season - not a good time of year to come if you want to avoid crowds. Besides, it's the hottest time of the year.
If you want more information about one of the main natural parks in Spain, go and visit this website:
http://www.ordesa.net/