The WWF oasis of Monte Arcosu is located within the Gutturu Mannu Regional Nature Park. The oasis covers 3600 hectares falling within the territories of Uta, Siliqua and Assemini. It is part of the largest thermophilic scrub forest in the Mediterranean. Of great value is the biodiversity hosted: naturalistic research has determined the presence of 219 species of lichens, 520 plant species identified, the existence of 46 endemisms should be noted, including Barbarearupicola, Helichrysum montelinasanum and Anchusa formosa. Also significant is the presence of wildlife: endemic are the Sardinian deer, the weasel, the Sardinian marten the Sardinian fox, and the wild cat. During the winter season, it is easy to glimpse the Iglesiente geotriton, an urodelo amphibian exclusive to southwestern Sardinia. Peregrine falcons, Sardinian goshawks and golden eagles nest in the reliefs.