Just minutes north of Albuquerque (off of I-25, exit 242) in Bernalillo, is Coronado State Monument where Francisco Vásquez de Coronado—with 300 soldiers and 800 Indian allies from New Spain—entered the valley while looking for the fabled Seven Cities of Gold. Instead he found villages inhabited by prosperous native people. Coronado's party camped near the Tiwa pueblo of Kuaua, one of the many villages encountered by the explorers.
The ladder leads down into a 'kiva' where ceremonies were held. You are not allowed to take pictures there because of the religious significance. Too bad...there are some amazing murals on the walls.