The University of Illinois at Urbana–Champaign (U of I, University of Illinois, UIUC, or simply Illinois) is a public research-intensive university in the U.S. state of Illinois. A land-grant university, it is the flagship campus of the University of Illinois system. The University of Illinois at Urbana–Champaign (founded, 1867) is the second oldest public university in the state (after Illinois State University), and is a founding member of the Big Ten Conference. It is a member of the Association of American Universities and is designated as a RU/VH Research University (very high research activities). The campus library system possesses the second-largest university library in the United States after Harvard University
The university comprises 17 colleges that offer more than 150 programs of study. Additionally, the university operates an extension that serves 2.7 million registrants per year around the state of Illinois and beyond. The campus holds 647 buildings on 4,552 acres (1,842 ha) in the twin cities of Champaign and Urbana (together known as Champaign–Urbana); its annual operating budget in 2011 was over $1.7 billion.
The main research and academic facilities are divided almost evenly between the twin cities of Urbana and Champaign. The College of Agriculture, Consumer, and Environmental Sciences' research fields stretch south from Urbana and Champaign into Savoy and Champaign County. The university maintains formal gardens and a conference center in nearby Monticello at Allerton Park. Four main quads compose the center of the university and are arranged from north to south. The Beckman Quadrangle and the John Bardeen Quadrangle occupy the center of the Engineering Campus. Boneyard Creek flows through the John Bardeen Quadrangle, paralleling Green Street. The Beckman Quadrangle is primarily composed of research units and laboratories, and features a large solar calendar consisting of an obelisk and several copper fountains. The Main Quadrangle and South Quadrangle follow immediately after the John Bardeen Quad. The former makes up a large part of the Liberal Arts and Sciences portion of the campus, while the latter comprises many of the buildings of the College of ACES spread across the campus map.
The campus is known for its landscape and architecture, as well as distinctive landmarks. It was identified as one of 50 college or university 'works of art' by T.A. Gaines in his book The Campus as a Work of Art. The campus also has a number of buildings and sites on the U.S. National Register of Historic Places including Harker Hall, Astronomical Observatory, Louise Freer Hall, The Main Library, The Experimental Dairy Farm Historic District, and Morrow Plots. U of I's Willard Airport is one of the few airports owned by an educational institution.