Cascais and its municipality are located in the far western of the Lisbon Peninsula, which borders to the north with Sintra, to the east with Oeiras and to the south and to the west with the Atlantic Ocean. It has its most western point in the shallow, and the most Oriental in Talaíde, on the right bank of the Ribeira of the slab. Its northernmost point, as well as the highest one, lies in the feather, which rises at 465 meters. Similarly to the other municipalities of the Lisbon Peninsula, it presents a relief whose most striking elements of the landscape are usually the valleys of the Ribeiras, narrow and embedded, and whose most relevant examples are the valleys of the ribeiras of the Foz do Winch, from the vineyards, from Penha long, from Caparidee Ribeira of the slab. 10  They add to these some spot reliefs, such as the Moor Cabeço, the Alto de bicease and the Fat head mount .
The Northeast quadrant is dominated by the Serra de Sintra, and there are the highest altitudes that decrease gently when further south, in its transition to the Cascais platform. This very regular platform has a soft slope to the south (up to the shallow cable) and corresponds to a marine abrasion surface.  The average altitude in these areas is between 250 and 350 meters (Malveira da Serra, Janes, Biscay), which rarely exceeds the 400 meters . In this area, the coast is predominantly steep, with the formation of several caves like the mouth of hell, and whose cliffs can reach 100 meters.  The only exception is in the area of the big beach of the winch, an extensive sandy area that, at the hydrological level, leads to the occurrence of infiltration phenomena and the disorganization of the drainage network.