Red Butte Canyon, home to the beautiful Red Butte Gardens, and some great east bench hiking trails, the area is also notable for one other thing, the old Sandstone quarry high on the hillside.
Sandstone from this quarry was used to make foundations for some of the earliest homes in Salt Lake City. Once the initial phase of "log cabin" building had diminished and more substantial homes and commercial buildings were being erected, sandstone from this quarry was cut and shaped to make those foundation stones. Red rock was also used for trim, and in some cases, the entire structure all together.
Stones from the Red Butte Quarry were also used initially for the foundation of the Mormon Temple, but when it was discovered that the some of the lower stones were cracking under the weight of the upper ones, it was decided to remove all of the sandstone foundation blocks and replace them with granite blocks from Little Cottonwood Canyon. The removed stones were most likely cut into smaller stones and used in other structures but this is not known for sure. 
The upper quarry is easily seen from the trails just above Red Butte Gardens, and can be accessed with a short hike.