Dramatic sea cave west of Cascais where Atlantic waves thunder through limestone cliffs — a natural spectacle.

One of the Estoril Coast's most dramatic natural spectacles, Boca do Inferno — 'Mouth of Hell' — is a sea cave and cliff archway carved by the Atlantic into the limestone rocks just west of Cascais. When waves surge through the narrow chasm, the roar and spray fully justify the evocative name. The site gained literary fame when the occultist Aleister Crowley staged his own fake disappearance here in 1930, leaving behind a dramatic note — a story that adds a layer of mystery to an already compelling spot. A short coastal path leads from Cascais, making it an ideal photo stop on any itinerary.