The Yorktown Heights building, housing the headquarters of IBM Research, is situated on private land not generally accessible to the public, is a large crescent-shaped structure consisting of three levels with 40 aisles each, radiating out from the center of the circle described as the crescent. Due to this construction, none of the offices have windows. The lowest level is partially underground in some areas toward the shorter side of the crescent, which also leads to the employee parking lots. A large overhang protrudes from the front entryway of the building, and faces the visitor parking lot. The building houses a library, an auditorium and a cafeteria. It was designed by the architect Eero Saarinen and built in 1956–1961.