Cutthroat Castle, an Ancestral Puebloan ruin located in the Hovenweep National Monument, Colorado, USA. Ancestral Puebloans, also known as the Anasazi, were a Native American civilisation that existed from approximately 100 CE to 1600 CE and inhabited the present-day Four Corners region of the United States. Hovenweep National Monument preserves six clusters of ancient villages that were built over 700 years ago. Cutthroat Castle is one of the most notable ruins within the monument. It is situated on a ridge and consists of multiple rooms and structures built using sandstone blocks.