The largest one of them, Wupatki Pueblo, used to be a home to around hundred people. Even today its past splendor can be easily appreciated:
Box Canyon and Lomaki Pueblo:
These pueblos were built around 800-years ago, most likely by ancestors of today's Hopi and/or Zuni people. Shortly after being built, they got abandoned and their inhabitants settled at a different location. Interestingly, the same happened to the pueblos located within today's Mesa Verde NP. Moreover, those two events happened around the same historical time. Still, we do not know what motivated Ancestral Puebloans to abandon their perfectly functional houses and start new communities elsewhere.