Room 124A is the San Juan kiva emplaced into Room 124W in the mid-late 1100s. The kiva measures 5 m in diameter. Thirteen strata were identified in kiva 124A including roof-fall, a floor complex, and feature-related deposits. Twenty features were recorded in the kiva. It had a central hearth, deflector, bench around its perimeter, ventilator tunnel and shaft, wall niches, probable sipapu, four evenly spaced pilasters, storage pit, and other pits of unknown purpose. The wall of the 124A kiva exhibited a mural with the design much simpler than what was found in the adjacent Room 121A kiva. Stratigraphy, ceramics, and the architectural style indicate that the kiva was built sometime in the mid-late 1100s and used into the 1280s.