Perhaps no other area offers as much evidence into the Ancestral Puebloan culture as Mesa Verde National Park. Several thousand archaeological sites have been found, and research is ongoing to discover more. The carved-out homes and assorted artifacts, many of which are displayed at the park's Chapin Mesa Archeological Museum, belonged to ancestors of today's Hopi, Zuni, and Pueblo tribes, among others. Due to the sensitive nature of these sites, hiking in the park is restricted to designated trails, and certain cliff dwellings may be accessed only on ranger-led tours during the peak summer season.