Ladd Library is the modern, four-story building in the center of the campus, behind the Coram Library building and beside the Carnegie Science Building. The entrance is across the terrace from Coram. Officially known as the George and Helen Ladd Library, it is more commonly known as Ladd Library or simply, "Ladd." It houses 620,000 catalogued volumes, 2,500 serial subscriptions and 27,000 audio/video items. The first three floors of Ladd opened in 1973. The overall cost was $3.5 million and was partially funded with a $500,000 challenge grant from the Kresge Foundation.