Monfragüe National Park is where the Rivers Tiétar and Tajo meet. The Tajo is the longest river on the Iberian peninsula and bisects Extremadura before it flows through Portugal and out into the Atlantic at Lisbon. Monfragüe is world-famous for its colonies of birds especially the Griffon Vulture but there is much more to the park than the birds. The whole area covers 18,396 hectares and most of it is ancient forests where a rich diversity of animal life flourishes. A great deal of the park is closed to visitors — for the safety of the visitors and the encouragement of the wildlife — but the park has excellent routes of varying length and degree of difficulty. The routes are all very well marked and colour-coded so everyone can enjoy the walking.