The Open university is one of the biggest universities in the UK for undergraduate education. There also are a number of full-time postgraduate research students based on the 48-hectare university campus where they use the OU facilities for research, as well as more than 1000 members of academic and research staff and over 2500 administrative, operational and support staff. The OU was established in 1969 and the first students enrolled in January 1971. The University administration is based at Walton Hall, Milton Keynes in Buckinghamshire, but has regional centres in each of its thirteen regions around the United Kingdom. It also has offices and regional examination centres in most other European countries.