Southernmost branch of Sabini Mountains, it marks the eastern border of the Roman Countryside. In the south and in the east, it is delimited by Aniene Valley. The naturalistic richness of Monti Lucretili Regional Park lies in the particular configuration of the pre-Apennine landscape, where the proximity to the sea has contributed to the formation and coexistence of biotopes determined by different microclimates, the latter given to different exposures and influenced by the variation of the circulation of the air masses within the mountain group.