The university campus is characterized by its grassy open spaces and tree cover. The university landscape is well maintained, and many students take advantage of the spacious lawns and large shade trees. The campus is bounded on the north by the Lloyd Expressway, the south by Lincoln Avenue, west by Rotherwood Avenue, and on the east by Weinbach Avenue. Walnut Street bisects the campus. Sesquicentennial Oval, the ceremonial entrance to campus, opens off of Lincoln Avenue. The oval was named in 2004 in commemoration of the university's 150th anniversary. The Schroeder Family School of Business, McCurdy Alumni Memorial Union, Sampson Hall / Mann Health Center, Hyde Hall, Olmsted Administration Hall, Clifford Memorial Library, and Koch (pronounced Cook) Center for Science and Engineering (all sectors of the original and later additional science/engineering buildings) surround Sesquicentennial Oval. Most of the buildings follow an old limestone motif, and renovations generally emulate the rest of the building.