Nun’s Well is an ancient, underground water resevoir, located at Europa Point. It is sited on the Europa New Road, at the north end corner of Europa Flats, opposite the south entrance to Keightley Way Tunnel.

The present access into the cistern is by means of a flight of steps on a platform constructed on the eastern side of the building and below its present urban level. These steps lead to a door which was constructed at floor level of the cistern itself.

The steps adjoin the main building (a small castle like structure) which has deteriorated badly and the paint of which has weathered yellow. It was constructed by the Royal Engineers in 1988 when the whole of the ancient building was given a full refurbishment and a main building added to enhance it as a tourist attraction.

The history of this site is inconclusive since very little is known about the origins of the well or of the whole construction itself. Historical references to this site are scarce and up to the present, very little information has been available.

In May 1987 The Royal Engineers, 60 FDS on EX-ninth shot, carried out a site investigation (prior to the refurbishment of the site) and they summarised it as follows:

"Nun's Well consists of two large underground chambers. The well is thought to be a Moorish bath or cistern, however it could also be from an even earlier period of Gibraltar’s past. In 1753 the governor had the underground chambers cleaned and they were used to provide water for the soldiers. In 1802, the Duke of Kent arrived in Gibraltar, he set up a brewery at Europa called Brewery Yard, next to the Nun’s Well. The water from the chambers was used for brewery purposes. This brewery was later converted into Brewery Barracks."