Office for Religious Life has a Center for Inter-Religious Community, Learning, and Experiences (CIRCLE) on the third floor of Old Union. It offers a common room, an interfaith sanctuary, a seminar room, a student lounge area, and a reading room, as well as offices housing a number of Stanford Associated Religions (SAR) member groups and the Senior Associate Dean and Associate Dean for Religious Life. Most though not all religious student groups belong to SAR. The SAR directory includes organizations that serve atheist, Bahá’í, Buddhist, Christian, Hindu, Islam, Jewish, and Sikh groups, though these groups vary year by year. The Windhover Contemplation Center was dedicated in October 2014, and was intended to provide spiritual sanctuary for students and staff in the midst of their course and work schedules; the center displays the "Windhover" paintings by Nathan Oliveira, the late Stanford professor and artist. Some religions have a larger and more formal presence on campus in addition to the student groups; these include the Catholic Community at Stanford and Hillel at Stanford. Greek life Fraternities and sororities have been active on the Stanford campus since 1891 when the university first opened. In 1944, University President Donald Tresidder banned all Stanford sororities due to extreme competition. However, following Title IX, the Board of Trustees lifted the 33-year ban on sororities in 1977. Students are not permitted to join a fraternity or sorority until spring quarter of their freshman year. As of 2016 Stanford had 31 Greek organizations, including 14 sororities and 16 fraternities. Nine of the Greek organizations were housed (eight in University-owned houses and one, Sigma Chi, in their own house, although the land is owned by the university). Six chapters were members of the African American Fraternal and Sororal Association, 11 chapters were members of the Interfraternity Council, seven chapters belonged to the Intersorority Council, and six chapters belonged to the Multicultural Greek Council. Stanford is home to three unhoused historically National Pan-Hellenic Council (NPHC or "Divine Nine") sororities (Alpha Kappa Alpha, Delta Sigma Theta, and Sigma Gamma Rho) and three unhoused NPHC fraternities (Alpha Phi Alpha, Kappa Alpha Psi, and Phi Beta Sigma). These fraternities and sororities operate under the African American Fraternal Sororal Association (AAFSA) at Stanford. Seven historically National Panhellenic Conference (NPC) sororities, four of which are unhoused (Alpha Phi, Alpha Epsilon Phi, Chi Omega, and Kappa Kappa Gamma) and three of which are housed (Delta Delta