The university passed a statute in 1875 allowing its delegates to create examinations for women at roughly undergraduate level. The first four women's colleges were established due to the activism of the Association for Promoting the Higher Education of Women (AEW). Lady Margaret Hall (1878) was followed by Somerville College in 1879; the first 21 students from Somerville and Lady Margaret Hall attended lectures in rooms above an Oxford baker's shop. The first two colleges for women were followed by St Hugh's (1886), St Hilda's (1893) and St Anne's College (1952). In the early 20th century, Oxford and Cambridge were widely perceived to be bastions of male privilege, and it was not until 7 October 1920 that women became eligible for admission as full members of the university and were given the right to take degrees. In 1927 the university's dons created a quota that limited the number of female students to a quarter that of men, a ruling which was not abolished until 1957. However, before the 1970s all Oxford colleges were for men or women only, so that the number of women was limited by the capacity of the women's colleges to admit students. It was not until 1959 that the women's colleges were given full collegiate status. In 1974, Brasenose, Jesus, Wadham, Hertford and St Catherine's became the first previously all-male colleges to admit women. In 2008, the last single-sex college, St Hilda's, admitted its first men, so that all colleges are now co-residential. By 1988, 40% of undergraduates at Oxford were female; the ratio was about 46%:54% in men's favour for the 2012 undergraduate admission. The university is a "city university" in that it does not have a main campus; instead, colleges, departments, accommodation, and other facilities are scattered throughout the city centre. The Science Area, in which most science departments are located, is the area that bears closest resemblance to a campus. The ten-acre (4 hectare) Radcliffe Observatory Quarter in the northwest of the city is currently under development. However, the larger colleges' sites are of similar size to these areas. Iconic university buildings include the Sheldonian Theatre used for music concerts, lectures, and university ceremonies; and the Examination Schools, where examinations and some lectures take place. The University Church of St Mary the Virgin was used for university ceremonies before the construction of the Sheldonian. Christ Church Cathedral uniquely serves as both a college chapel and as a cathedral. In 2012–13, the university built the controversial one-hectare (400m × 25m) Castle Mill development of 4–5-storey blocks of student flats overlooking Cripley Meadow and the historic Port Meadow, blocking views of the spires in the city centre. The development has been likened to building a "skyscraper beside Stonehenge". The detective novel Gaudy Night by Dorothy L. Sayers, herself one of the first women to gain an academic degree from Oxford, is largely set in a (fictional) women's college at Oxford, and the issue of women's education is central to its plot. The University Parks are a 70-acre (28 ha) parkland area in the northeast of city. It is open to the public during daylight hours. As well as providing gardens and exotic plants, the Parks contains numerous sports fields, used for official and unofficial fixtures; and also contains sites of special interest including the Genetic Garden, an experimental garden to elucidate and investigate evolutionary processes. The Botanic Garden on the High Street is the oldest botanic garden in the UK. It contains over 8,000 different plant species on 1.8 hectares (4½ acres). It is one of the most diverse yet compact major collections of plants in the world and includes representatives of over 90% of the higher plant families.
The Harcourt Arboretum is a 130-acre (53 ha) site six miles (10 km) south of the city that includes native woodland and 67 acres (27 ha) of meadow. The 1,000-acre (4 km2) Wytham Woods are owned by the university and used for research in zoology and climate change. There are also various collegiate-owned open spaces open to the public, including Bagley Wood and most notably Christ Church Meadow. As a collegiate university, Oxford's structure can be confusing to those unfamiliar with it. The university is a federation, comprising over forty self-governing colleges and halls, along with a central administration headed by the Vice-Chancellor. Academic departments are located centrally within the structure of the federation; they are not affiliated with any particular college. Departments provide facilities for teaching and research, determine the syllabi and guidelines for the teaching of students, perform research, and deliver lectures and seminars.
Colleges arrange the tutorial teaching for their undergraduates, and the members of an academic department are spread around many colleges. Though certain colleges do have subject alignments e.g., Nuffield College as a centre for the social science, these are exceptions, and most colleges will have a broad mix of academics and students from a diverse range of subjects. Facilities such as libraries are provided on all these levels: by the central university the Bodleian, by the departments individual departmental libraries, such as the English Faculty Library, and by colleges each of which maintains a multi-discipline library for the use of its members. Two university proctors, elected annually on a rotating basis from two of the colleges, are the internal ombudsmen who make sure that the university and its members adhere to its statutes. This role incorporates student welfare and discipline, as well as oversight of the university's proceedings.
The university's professors are collectively referred to as the "Statutory Professors of the University of Oxford". They are particularly influential in the running of the university's graduate programmes. Examples of Statutory Professors are the Chichele Professorships and the Drummond Professor of Political Economy. The various academic faculties, departments, and institutes are organised into four divisions, each with its own Head and elected board. They are the Humanities division; the Social Sciences Division; the Mathematical, Physical and Life Sciences Division; and the Medical Sciences Division. The University of Oxford is a "public university" in the sense that it receives some public money from the government, but it is a "private university" in the sense that it is entirely self-governing and, in theory, could choose to become entirely private by rejecting public funds.