It is an unusual tourist attraction perhaps but one of the sights to see in Lisbon is the Aquaducto das Águas Livres (‘aqueduct of free waters’) which was built in 1835 to bring the city its first clean drinking water. The 109 stone arches extend from Lisbon across the hills 18 miles into Canecas. The inaugural stone was laid at the Mãe de Água (‘mother of water’), which now stands behind the Socialist Party headquarters on Largo do Rato.

The reservoir can hold 5,500 cubic metres of water. The cool stone chamber, with its floating platform, is now used for art exhibitions. Climb onto the roof for a wonderful view of the city. Take a train from Rossio to Campolide to see the aqueduct at its most impressive – 65m high. Enthusiasts should also visit the Museu da Água in a former pumping station on Rua do Aviela 12, Santa Apolonia (tel: 21 813 5522).