Lisbon was formerly provided with clean drinking water by means of the Aqueduct of Free Waters (1729-48), built by Manuel da Maia and stretching for more than 18 km (11 mi) from the water source on the outskirts of the city. It survived the 1755 earthquake, and today its most graceful section consists of 14 arches that soar 200 feet over the pretty neighborhood square of Largo das Amoreiras. The aqueduct itself is off-limits unless you book a group tour, but the square is also the site of the associated Mãe d'Agua, an internal reservoir capable of holding more than a million gallons of water. This extraordinary structure is used for art exhibitions and other cultural displays, giving you the chance to view the vast holding tank, the lavish internal waterfall, and the associated machinery.
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