and five years later, it reopened as a gymnasium and community facility. The building's interior contains a basketball court with synthetic flooring, and there are offices and lockers in its northern end. Basement Riverside Church's basement includes several modern amenities such as a 250-seat movie theater and a gymnasium with a full-size basketball court. The section of the basement under the nave has a double-height ceiling; an assembly hall is on the southern side of this space while the gymnasium is on the northern side. The assembly hall has a stone floor and walls, and there are six arched stained-glass windows on the eastern wall and one rectangular stained glass window on the south wall, as well as cabinets that contain two Heinrich Hofmann paintings (see ). It also has a wooden ceiling that is supported by stone arches, with lanterns suspended from the ceiling and a stage in the northern portion. A kitchen is east of the stage, and a corridor runs adjacent to the western wall of the assembly room and gymnasium. The basement originally included a four-lane bowling alley that was adjacent to the assembly floor. It was later removed and converted into storage space. There is a two-story, 150-space parking lot underneath the MLK Wing. Organs The two Riverside Church organs are located in the chancel and the seating gallery. The chancel organ is the 14th largest in the world . It was furnished in 1930 by Hook and Hastings, and was originally criticized as mediocre. Aeolian-Skinner built an organ console in the chancel in 1948 and replaced the chancel organ in 1953–1954, and the ceiling above the chancel and the front of the nave was coated with sealant to improve the chancel's acoustic qualities. The chancel organ was opened with a concert in March 1955 with a concert by Virgil Fox and the New York Philharmonic Symphony Orchestra, attended by 3000 people. In 1964, another Aeolian-Skinner organ was installed within the eastern wall of the nave's seating gallery; three years later, Anthony A. Bufano installed a five-manual console for the gallery organ. M. P. Moller built another stop for the gallery organ, the Trompeta Majestatis, in 1978. Two years later, the chancel organ received a new principal chorus with the addition of the Grand Chorus division. In the 1990s, the console was rewired, the chancel organ was cleaned, and the ceiling was covered with ten