Cascais Cliff Path (Boca do Inferno Loop)

The Cascais Cliff Path forms a 5 km loop starting at the Boca do Inferno sea chasm on Estrada de Birre, Cascais, Portugal, easily reached by train from Lisbon (about 40 minutes to Cascais station) followed by a 2 km walk or bike ride along the coast to the trailhead; no permit is needed and the path is open at all hours, though visibility is best in daylight. The route stays close to sea level with a maximum elevation of about 30 m, making it one of the gentlest coastal walks in the Lisbon region, following a paved and packed-gravel promenade for most of its length with a short unpaved cliff-edge section near Boca do Inferno itself. Shade is minimal, as the path runs along open cliffs and seafront, but the short distance keeps sun exposure manageable even in summer. Key landmarks include the Boca do Inferno blowhole, where Atlantic swells crash into a collapsed sea cave, the lighthouse at Cabo Raso, and views back toward Cascais marina. The loop has no meaningful turn-around point since it is short and circular, though walkers can shorten it by returning directly along the seafront promenade rather than completing the full loop. There are no huts or water sources directly on the cliff section, but Cascais town, at the loop's end, has cafes, restrooms, and shops. The path is popular at sunset, when the Atlantic light over the chasm draws photographers, and can become crowded with tour groups visiting Boca do Inferno by coach during midday hours.