Carleton College (/ˈkɑːrltɪn/ KARL-tin) is a private liberal arts college in Northfield, Minnesota. Founded in 1866, the college enrolled 2,105 undergraduate students and employed 269 faculty members in fall 2016. Carleton is one of the few liberal arts colleges that runs on the trimester system.[7][8] The 200-acre main campus is located between Northfield and the 800-acre Cowling Arboretum, which became part of the campus in the 1920s.[9] The architecture of campus buildings ranges from Collegiate Gothic to contemporary, with the oldest built in 1872 and the most recent in 2011.[10]