The Norman Undercroft lies beneath the Castle’s Great Hall but, unlike the latter, it retains much of its original eleventh century appearance.
This would always have been a utilitarian space, and such spaces tended to survive intact because there was little desire to remodel them as fashions changed. The structural role of the undercroft also meant that it was impossible to make any significant changes, and so it has remained very well preserved.
Today, it serves as the bar for University College, and is popularly referred to as the 'Undie'.