The Sintra-Cascais Natural Park is 42 kilometres west of the city of Lisbon and in the southwest of Sintra.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. Source: https://en.wikipedia.org/wiki/Cabo_da_Roca