The cliff behind the Costa da Caparica sand is older than any road that reaches it. Geologists read the Arriba Fóssil as Miocene and Pliocene sediment — layers of clay, sand and shell laid down when this shoreline lay beneath the sea. The escarpment runs some thirteen kilometres and lifts to roughly seventy metres above the beach. Portugal protected it in 1984 as the Paisagem Protegida da Arriba Fóssil da Costa da Caparica. From Lisbon Atlantic Coast Guided Quad Bike Tour tours move along the sand tracks and pine terraces at its foot. Settlement here is recent by Portuguese measure. Avieiro fishermen from the Vieira de Leiria lagoons drifted south in the nineteenth century and built plank houses above the tideline; the village took its name from the Convento dos Capuchos, founded in 1558 on the ridge at Almada. For centuries the peninsula faced Lisbon across open water and little else. Cristo Rei was inaugurated in 1959. The Ponte 25 de Abril opened in 1966, and the journey from the capital collapsed from a ferry crossing into twenty minutes of motorway. What survives is a coast that resisted the resort logic applied elsewhere. Thirty kilometres of open Atlantic beach run south from Trafaria to Fonte da Telha, backed by the Mata Nacional dos Medos, a stone-pine forest planted from the eighteenth century to hold the marching dunes in place. Juniper thickets still bind the sand. Surfers read the beach breaks by number, and the Transpraia narrow-gauge train has carried bathers along the dune line each summer since 1960. The machines locals call moto-quatro follow the same firebreaks the foresters cut. Access to the shoreline and forest tracks costs 0 EUR. Southward the geology grows stranger. Lagoa de Albufeira opens and closes its mouth to the sea with the season. At Cabo Espichel, a sanctuary begun in the eighteenth century stands above cliffs where sauropod footprints, pressed into rock roughly 150 million years ago, climb the face toward the lighthouse. Behind it, the limestone wall of the Serra da Arrábida turns the water an improbable green. Costa da Caparica quad bike trips and From Lisbon Atlantic Coast Guided Quad Bike Tour tickets exist because this terrain reveals itself only at ground level, one dune crest at a time.