Red Rocks Amphitheatre is used to hold concerts in the open-air. It is made of rock near Morrison Colorado. You need to go 16 km towards west from Denver to reach the concert place. The stage is surrounded by large rocks. At the back of the stage, you can see a large rock whose shape appears as disc type. A large vertical rock is situated at the right to the stage and numerous great outcrops are located at the stage left. The stage lies exactly in between them where nearly 9525 people can sit together to see a concert. The amphitheatre lies at the elevation of 6450 feet and the Red Rocks Park located around the stage is spread up to 868 acres. The City and County of Denver, Colorado has control over the amphitheater which lies in Red Rocks Park. The place is amazing for a concert.
Source: https://en.wikipedia.org/wiki/Red_Rocks_Amphitheatre