In the sixteenth century a Franciscan friar called Francisco de Tembleque looked at the dry highlands north-east of Mexico City, where villages had trouble finding clean water, and decided to bring it from springs on the slopes of a volcano forty-five kilometres away. The result, built between 1553 and about 1571 with the labour of local Indigenous communities, is one of the longest aqueduct systems of its age in the Americas, and it still stands on a high arcade of stone arches crossing a valley. The longest arcade runs for nearly a kilometre, and the tallest arch is about forty metres high, a slender, elegant bridge on thin piers, which is why you can see it for miles across the plain.
What makes it special is a mix of European and Mesoamerican engineering, with Roman-style arches built using local techniques, mortar made with the sap of the nopal cactus, and a design that allowed for the earthquakes of the region. It was listed by UNESCO in 2015. The water ran by gravity alone for decades, and the villages of the plain, such as Otumba, depended on it.
The country around is high, windy and open, a plateau at around two and a half thousand metres, with fields of maguey, the agave that is tapped for pulque, a sour, milky drink that is the traditional tipple of the region. Apan, not far away, is the pulque capital, and you can stop for a glass, or for barbacoa, slow-cooked lamb, served on Sundays with consommé and tortillas. Santiago Tepeyahualco and San Felipe Teotitlán, the nearest villages, are small, and have shops and a church, but not much else, so fill the tank in a larger town such as Apan, Tulancingo or Pachuca.
The riding is straightforward, with long, straight highways, rolling hills and wide skies. Local roads are less predictable, with potholes, speed bumps called topes that appear without warning and slow trucks and tractors. The weather is cool at height, even in summer, with afternoon storms from June to September, and cold nights in winter, so bring layers. The dry months, from November to April, bring the clearest views and the best light on the stone, and early morning is the best time to see the arches in a clear, golden glow.