The Convent of the Order of Christ needed a water supply, and the answer was to construct this magnificent six-kilometre aqueduct to conduct water from the four springs at Pegões.

The project began in the 1590s and was planned by the Italian military architect Filipe Terzio who had been hired by the Portuguese crown.

Work would continue for 21 years, and Terzio wouldn’t live to see it completed.

The aqueduct is most impressive when it crosses the steep Vale da Ribeira dos Pegões, with two tiers of arches (ogival underneath, round at the top) reaching a maximum height of 30 metres.

If you’re brave enough you can even walk along the conduit at the top.