The cape is located within the Sintra-Cascais Natural Park, 42 kilometres northwest of the urbanized area of Lisbon and 18 kilometres northwest of Sintra. Its location (38°47′N 9°30′W) is inscribed on a stone plaque, located on a monument at the site.
The western coast is a mixture of sand beaches and rocky cliff promontories: around Cabo da Roca, cliffs are more than 100 metres in height, and cut into crystalline rocks, composed of strongly folded and faulted sedimentary units. These forms are disturbed by dikes and small beaches. This promontory of “high” beaches is the extreme western immersion of the ancient eruptive Sintra massif, as evident from the rose-coloured granite in the north and syenite of the Ribeira do Louriçal in the south. In the vicinity of the Cape, there are geomorphological examples of gabbro-diorite, volcanic breccia, and granite.
Part of the granite formations show evidence of strong coastal erosion, while in other areas there are limestone deposits embedded in the granite.
Much of the vegetation in this cape are low-lying and adapted to saltwater and windy conditions. Once home to a variety of plant life, Cabo da Roca has been overrun with the invasive plant species Carpobrotus edulis. This creeping, mat-forming plant, a member of the Aizoaceae succulent family, was introduced as ground cover by local residents several decades ago, but now covers much of the arable land on Cabo da Roca.
Many migratory and marine birds roost temporarily along the cliffs and protected coves of the coastal area.