Mesa Verde in Colorado is known for its ancient Puebloan cliff dwellings built in alcoves and overhangs of the sandstone cliffs. The ruins were discovered in the 1880s and the area was made a national park in 1906. The cliff dwellings and other structures were built by the Ancient Puebloan people between the 12th and 14th centuries from sandstone and other local rock. The park landscape and ruins provide insight into the geology, environment, and culture of the Ancient Puebloans who lived there hundreds of years ago.