Ponte da Arrábida

The Ponte da Arrábida crosses the Douro between Porto and Vila Nova de Gaia in a single concrete arch spanning 270 metres — the longest concrete arch in the world when it opened in 1963. Portuguese engineer Edgar Cardoso designed the bridge using novel calculation methods he developed himself, allowing the slender arch to leap the wide river without intermediate piers. It carries the A1 motorway and the IC23 inner ring road, and is listed as a Portuguese cultural monument. The bridge is best experienced from the riverside promenades below, where its sweeping curve frames long views up and down the Douro, particularly striking at dusk when low light warms the bare concrete surface.