Regensen (original Latin name: Collegium Domus Regiæ) is a dormitory for students at the University of Copenhagen and Technical University of Denmark. It is situated in the heart of the old city and is a neighbour to Rundetårn. It was inaugurated 1 July 1623, but it burned down along with the rest city in the Great Fire of Copenhagen in 1728. It was, however, rebuilt the same year.
It is the second oldest of the old dormitories of the University of Copenhagen, and many old student traditions live on making the place very lively. Students of the University of Copenhagen and the Danish Technical University (DTU), who have completed two years of studies and have an average grade of at least 7 (in the Danish grading system), can be considered for admission to one of its 99 rooms.
One room is traditionally reserved for an applying foreign exchange student, who can occupy it for one year.
The residents of Regensen organize themselves in small 'clubs' in which they gather to eat, drink and socialize. The current clubs are 'Gamle' ('Old'), 'PIP' (Primus Inter Parens), 'Ping', 'Skrap', 'HOF' (Carlsbergs HOF), 'Tilia', and 'Uglen' ('The Owl').