Presa de la Olla

The Presa de la Olla sits at the top of Paseo de la Presa, southeast of Guanajuato's historic center and inside the city's protected monument zone. Water was always short in this mining city: the drought of 1714 brought hunger and plague, and the town council resolved to build a reservoir on a plot known as La Olla Grande. Work began in 1741, the year Guanajuato was made a city; the reservoir first filled in 1747 and was declared finished in 1749. At least half the cost was paid by Vicente de Sardaneta y Legaspi, majority owner of the Rayas mine. In the mid-19th century the dam wall was raised and a smaller reservoir, San Renovato, was added beside it, finished in 1852.

The spot quickly became a place for outings. Around 1795 the intendant Juan Antonio de Riaño built a carriage road, and in the 1800s Paseo de la Presa filled with summer houses and gardens. Today the reservoir is framed by the Florencio Antillón and Las Acacias gardens, with a boat dock where small rowboats are rented and a statue of Hidalgo, cast in Italy and unveiled by Porfirio Díaz in the early 1900s.

Its big day is the opening of the floodgates. The city once opened several reservoirs each year to flush out silt and clean the riverbed; only the opening at La Olla survives, perhaps held, with gaps, since 1748. It welcomes the rainy season and is tied to the feast of San Juan on 24 June. Officials wave white handkerchiefs, the water pours out while a band plays Juventino Rosas's waltz Sobre las olas, and a street fair follows in Parque Florencio Antillón. It was declared intangible cultural heritage of the state in 2013, and drew about 10,000 people in 2024.