The Main Loop (Ruins, or Nature Trail on some maps) is the biggest tourist attraction of Bandelier National Monument. Virtually every visitor will walk among the ancient ruins and perhaps peek into the cave dwellings embedded into the sheer rock walls of the canyon. According to studies, the ruins were occupied by the ancestors of the current Cochiti Pueblo.

Guided walks are available; self-guided walks can be augmented with the available trail literature. Many different ruins are available to view, from Tyuonyi (a D-shaped pueblo reminiscent of the Chaco style), to cave dwellings, to "Long House", a row of dwellings adjacent to the cave dwellings and augmenting their capacity. Note that the track on the map does not include some areas just outside of the Visitors Center.