Cloisters Ruin Approximately 100 Metres North of Redbourne Hall

The Cloisters ruin, located approximately 100 metres north of Redbourne Hall, is a folly likely built in the late 18th century to early 19th century. It incorporates re-used medieval or later masonry and was constructed for the Carter Estate or the Duke of St Albans. The structure features squared limestone and coursed rubble with limestone ashlar dressings, and some brick is present in a blocked section of a window.

The north-south wall measures about 10 metres long and was originally part of a screen wall that connected to an arcaded screen wall located approximately 60 metres north of Redbourne Hall. The west face includes a central gabled section that is roughly 5 metres long and 5 metres high, featuring quoins and a pointed two-light window with a blocked lower section and a foiled Y-traceried head. To the right is a lower section about 3 metres long, which has a cross-shaped slit window in a rough gable, and to the left is a short section of tumbled wall approximately 2 metres long.

The rear of the ruin displays portions of two rubble arches that project at right angles from the central section. A section that connected to the arcaded wall to the south was demolished around 1980. The pointed window resembles those found in Redbourne Church, indicating that the folly may have been built for Rev Robert Carter Thelwall during the church's rebuilding and the estate's improvements in the 1770s to 1780s. Alternatively, the window might have been added later from a chapel on the south side of the chancel, which was converted into a mausoleum for the Dukes of St Albans in the early 19th century. The structure is in a state of decay at the time of the last survey, and the adjoining buildings are not of special interest.