Ex-Hacienda de Santa María Regla

Ex-Hacienda de Santa María Regla is the sister estate to San Miguel Regla, built in the eighteenth century as part of the silver-refining holdings of the Conde de Regla, Pedro Romero de Terreros. The hacienda is best known for the adjoining Prismas Basálticos, a canyon of hexagonal basalt columns formed by cooling volcanic lava roughly thirty-two million years ago and later exposed by the Río San Antonio, which the estate's builders incorporated into the property's water-management system for ore processing. The hacienda buildings themselves, constructed from quarried local stone, included refining courtyards, storage arches, and a small chapel typical of colonial haciendas de beneficio, where silver ore was crushed and amalgamated with mercury in the patio process before being shipped for coinage. Portions of the original structure remain standing amid the landscaped grounds that now form a public recreational area managed for visitors to the basalt columns, with walking paths that pass beneath the towering prisms and along the reservoir the hacienda's operators built to power ore-crushing machinery. Little of the industrial machinery survives, but the stone architecture, dam, and canal system remain visible evidence of how colonial mining wealth reshaped the local landscape, combining functional water engineering with the natural volcanic formation that today draws far more visitors than the hacienda's mining history alone would.