The Aqueduct of Querétaro is one of the finest surviving examples of colonial engineering in the Americas — 74 arches in pink stone stretching 1.3 kilometres across the valley northeast of the old city, reaching a maximum height of 23 metres. It was completed in 1738 and carried water from springs in the hills to the city's fountains for over a century before being decommissioned.
The best view is from the Mirador de los Arcos at the base of the structure, where the arches recede into the distance and the pink stone glows in the afternoon light. The surrounding neighbourhood of La Cañada has good restaurants and cafes making it a natural stop before or after. At night the aqueduct is lit up and makes for a good evening stroll — the whole stretch is pedestrianised.