El Deposito
San Juan, Philippines · built 1880
El Depósito (The Deposit) is an old underground water reservoir in the city of San Juan in Metro Manila, Philippines. It was built by the Spanish authorities in 1882 with a capacity of 15 million gallons to provide the residents of Manila and its surrounding areas with adequate water supply. The reservoir was historically known as the site where the onset of the Philippine Revolution through the Battle of San Juan del Monte took place in 1896.
Reservoir data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).