Six Upper Vallesian (Upper Miocene) fossil vertebrate sites have been found in the Cerro de los Batallones (Torrejón de Velasco, Madrid). These localities contain an exceptionally rich, varied and well-preserved vertebrate fauna. Carnivore species are strikingly well represented at Batallones 1 and 3, and large herbivore species, such as mastodons, rhinoceros and giraffes, are common in Batallones 2, 4 and 5. The mammalian association, together with the morphological features shown by the sedimentary fills of the mammal sites, enables an overall interpretation of these deposits as vertebrate traps. The study of these localities should offer a significant contribution to our understanding of the formation pattern of trap-like paleontological sites which so far have been typically reported in karstic-type systems. These new sites also will contribute to a better knowledge of some of the most scarce mammal groups in the Miocene fossil record