Castle Rock was founded in 1874 and incorporated as a town in 1881. It was named after a prominent rock formation in the area that resembles a castle tower.

The city is known for its historic downtown area, which features a variety of shops, restaurants, and cultural attractions, including the Castle Rock Museum and the Festival Park Amphitheater as well as its several parks and open spaces, including Castlewood Canyon State Park, which offers hiking trails, picnic areas, and scenic views of the surrounding mountains.