Situated between the two Pitiusa Islands, the nature reserve runs South of the island of Ibiza to the North of the island of Formentera, covering the channel that separates the two island, and occupying a surface area of 2,838.44 terrestrial hectares and about 9,012 marine hectares.
By virtue of Law 17/2001 of 19 December it was declared a protected space and nature reserve. The principal objectives of this protection are to conserve and improve the natural, cultural and ethnological heritage of this area. The most significant points of the reserve are its great variety of environments and different ecological characteristics.
The saline pools, in addition to providing a resting point for well-known birds such as flamingos (Phoenicopterus ruber) during their migration, they also represent a resource that has been modified in the course of time, demonstrating that it is possible for economic activities and conservation objectives, as established by the reserve’s managers, to live side by side.
The beaches are now the most important tourist attractions in the reserve with dunar chains meandering off the beach, and typical vegetation and animal communities that include the thousand-year old junipers.
There are also cliffs and rocky coastlines, which are home to very special vegetation and animal communities such as the Eleonor’s falcon (Falco eleonorae) and the osprey (Pandion heliaethus).
The small es Freus islands are more strictly protected in the reserve, and are classified within the area of strict nature reserve protection. Some of the most important islands are: s´Espalmador, s´Espardell and Es Penjats.
The sea, that accounts for 75% of the park, is of vital importance as a large part of the seabed is home to the best conserved Oceanic Posidonia underwater prairies in the whole of the Mediterranean. This marine plant plays a fundamental role, because, amongst other functions, it assists in the maintenance of fish populations and marine organisms, it oxygenates the water, keeping it clean and clear, protects beaches from the erosive effect of waves, and maintains the natural dynamics of the dunar systems.
Furthermore, the ruins of ancient civilizations and historic remains on the Pitiusas are also present in the nature reserve. They can be seen at the Punic settlement in Sa Caleta, and in the defence towers situated all along the coastline of the reserve.