Águas Livres Aqueduct

Lisbon sits beside a great estuary, yet for centuries it went thirsty: the Tagus is too salty to drink and the old springs of Alfama could not supply a growing city. In 1731 King John V decreed an aqueduct to bring fresh water from springs near Belas, paid for by special taxes on wine, meat and olive oil. The Italian Antonio Canevari, the engineer Manuel da Maia and João Frederico Ludovice, architect of the palace at Mafra, drew up the first plans; Custódio Vieira took charge around 1736, and the Hungarian-born Carlos Mardel finished the work. Water began flowing in 1748, about three times what the city had had before.

The great sight is the crossing of the Alcântara valley: 35 arches over 941 metres, 14 of them pointed. The tallest, the Arco Grande, completed in 1744, rises about 65 metres with a span close to 29 metres and is counted among the tallest pointed stone arches ever built. Pointed arches were chosen precisely because of that height and span. Inside the thickness of the structure run two narrow walkways flanking the water channel, lit and aired by small lanterns. The aqueduct came through the 1755 earthquake essentially intact, while much of the city around it fell.

The main line runs about 14 km, and the whole network of feeder aqueducts, galleries and reservoirs reached some 58 km, gathering water from dozens of springs. It ends at the Mãe d'Água das Amoreiras, a stone reservoir begun in 1745 and completed only in 1834, holding about 5,500 cubic metres. From there galleries carried water to public fountains across the city. The walkway atop the arches was closed to the public in 1852; popular legend links this to the murderer Diogo Alves, who supposedly threw victims from it, but the closure had nothing to do with him. The system kept working until 1967.

Today a railway, a motorway and a broad avenue pass beneath the arches, which only makes them look taller. The aqueduct, the Mãe d'Água and other parts of the system belong to the Museu da Água run by the water company EPAL, and the stretch over the valley, the Passeio dos Arcos, can once again be walked.

Getting there

The Alcântara arches stand in Campolide, within Lisbon, about 0.6 km from the neighbourhood of Campo de Ourique. Lisbon Humberto Delgado Airport (LIS) is about 7 km away. The walk over the arches starts from Calçada da Quintinha in Campolide; the Mãe d'Água reservoir is in Amoreiras, near Rato.