boca do inferno (hell's mouth) is unique rock formation on the edge of the ocean in cascais, portugal

amazing arch atlantic beach beautiful blue boca inferno cape cascais cave cliff coast coastal coastline destination eroded erosion europe formation geology grotto hell 039 mouth landmark landscape lisbon nature ocean outdoor portugal rock rugged scenic sea seascape seaside shore sightseeing sky stone summer tourism travel vacation view water wave hell#39aph39#s unique edge