Built to supply the capital with fresh water from the hills north of the city, the Aqueduto das Águas Livres is one of the most important engineering constructions from the 18th century. And fun fact: construction was actually funded by special levies on meat, olive oil and wine. It covers a total length of 14 kilometres from its main source in Caneças to its end at the reservoir of Mãe d’Água das Amoreiras. Fast forward to now, it belongs to the Water Museum which organises visits to the inside of the aqueduct. And the reservoir of Mãe d’Água das Amoreiras organises cultural events and temporary exhibitions.
Tue-Sun 10am-5.30pm. Admission: €4; concessions €2; free for under-17s.