Carved in Stone

High in the Sierras but deep in a lush river valley, slowly being taken over by vegetation, is the ruins of an ex-hacienda and gold/silver mine built by the Spaniards hundreds of years ago.
Last year we hiked to one section of this hacienda here and today we hiked to an area called Cinco Senores. The Spaniards engineered an ingenious array of water wheels, aqueducts, and crushers to use in extracting the metals so precious to them. (Of course they enslaved the local people to do all the work)
This photo is of the inside of an enclosure for one of the water wheels that turned a crusher (called a hammer mill) These walls were at least 30 feet high, and years of revolutions carved these marks in the stone walls.