Boca do Inferno is one of the most fascinating places in Cascais. Its name relates to the size and sheer force of the huge waves that batter these shores in winter. Literally translated as the Mouth of Hell, Boca do Inferno is the remains of an ancient cave with its wide-open mouth jutting into the sea in the form of an archway, through which the Atlantic waves crash relentlessly. Cascais Portugal is one of the most beautiful seaside towns in the world. Along the gorgeous coastline about 30 minutes west of Lisbon makes it perfect for a change of pace when visiting the urban center. Whether you want to lay on a beach, shop till you drop, dive into art, history, culture, or ice cream, Cascais offers plenty to keep you busy.