Presa de Valsequillo

Its official name is Presa Manuel Ávila Camacho, after the Puebla-born president who opened it in 1946, but in Puebla everyone calls it Valsequillo. It is the state's largest body of water, south of the capital where the Atoyac and Alseseca rivers meet. It was built to irrigate more than 33,000 hectares of the Valsequillo irrigation district, toward Tecamachalco and Tehuacán. Several villages and haciendas were flooded when it filled; the San Antonio del Puente hacienda survives as ruins.

The reservoir has been silting up: from 404.5 million m³ in 1946 its capacity fell to 303 in 1970 and 228 in 1998. A peninsula at San Baltazar Tetela almost splits it in two. Fossils of mammoths, mastodons, American horses and sabre-toothed cats have turned up on its banks, and the Hueyatlaco archaeological site lies here.

On 2 February 2012 the reservoir was listed as a Ramsar wetland, protecting 23,612 hectares. At least 97 migratory bird species use it, with ducks, herons and pelicans arriving from Canada and the US in winter; the chestnut-collared longspur (Calcarius ornatus) has also been recorded. Beside the water are the Valsequillo Wetland State Park and the 64-hectare Bicentenario park of dry scrub.

Pollution is the catch: the Atoyac, Alseseca and Zahuapan carry industrial and urban waste, the water is not drinkable and swimming is forbidden. Between 2008 and 2011 federal and state governments built and enlarged treatment plants to clean it up. Even so, the shore is a weekend outing, with jetties where boats leave for Isla de los Mapaches, kayaks, palapas, horse rides and snack stalls, and Africam Safari right next door.