Natural rock arches of the Orosei Gulf, Sardinia, Italy.  <B>Natural rock arches of the Orosei Gulf, Sardinia, Italy.</B><P>S. Barca, F. di Gregorio and G. Mulas</B><I><P> Department of Earth Sciences, University of Caglari, Caglari, Italy</I><P> Abstract<P> In this work the natural rock arches located along the Orosei gulf(eastern Sardinia, Italy) have been studied by means of a systematic inventory and specific investigations recorded on survey cards, with relative geomorphological maps. The features of theses natural arches (rock type, geologicalstructural conditions, erosional or concretion forms etc.) have thus been defined. Based on the date collected, each form has been classified according to its formation process, scientific interest and surrounding landscape. It has emerged that the rock arches in this area can for the most part be attributed to karstic morphogenetic processes, influenced to a greater or lesser extent by weathering and, subordinately, by littoral processes. The structural arrangement of the Mesozoic carbonate massif of the Orosei Gulf has also played a significant part in the evolution of these arches. The results are summed up in a map, which shows the areal distribution of the single forms, the degree of scientific or naturalistic interest, and suggestions for the conservation and fruition of the sites in a proper regional planning context, also through the organizations of the nature trails.<P>