The Reservoir Dam. Built at the beginning of the 20th century, this solid structure of hard stone retains water that overflows into the arroyo and canyon of El Charco during the rainy season. It also provides a panoramic view of the canyon to the west and the wetlands and reservoir to the east.  

The Iron Pipe. This very long aqueduct was built a few years after the dam, in order to carry water over a distance of one kilometer from the reservoir to the La Aurora textile factory, where it was used to generate electricity. The aqueduct ceased to function in the mid-20th century due to the drying up of the springs that fed the reservoir and the accumulation of silt.

The Water Mill. An unsuspicious small stone building in ruins, from Colonial times, which was a water mill used to grind grain or perhaps to treat wool, powered by a year-round stream that existed at that time. The base of the axle of the rotating wheel is still visible and, above, part of the stone aqueduct where the water flowed over that wheel. It is an important part of the historical site in El Charco.

The Hacienda. To the east edge of the Northers preserve lie the ruins of the old Hacienda Las Colonias, abandoned for more than 50 years. A barrel vault ceiling still remains in one buiding. Every month, during the full moon, traditional ritual steam-baths (temascal) are held in the round sweat-lodge, recently built for that purpose, as a regular monthly activity of the Botanical Garden.