The ruins of the priory lie approximately a quarter of a mile SW of Castle Acre village on low marshy ground near the river Nar. The remains of the castle keep stand on a motte surrounded by a bailey and earthworks on the east side of the village, and the extensive outer defences of the castle enclosed the priory site as well as the village. In the centre of the village is the Bailey Gate, originally the north entrance to the bailey. The extent of the priory enclosure can be gained from the position of the gatehouse of c.1500, to the north of the priory church. The layout of the monastery is still clearly discernible.

There are impressive standing remains, especially of the facade of the 12thc. church. This had a nave of seven bays and a choir of two, both aisled. The E end was triapsidal. A pair of towers surmounted the westernmost bays of the nave aisles. There was a crossing tower and transepts, the latter with an apsidal chapel apiece. The walls of the nave and transepts stand to a height of several feet in places. The plan, and in some cases, ornament of the nave piers (exceptionally varied, as a group) are still discernible. What survives of the south arcade are the arch, gallery and upper storey of the westernmost bay (bay 7), forming the north face of the SW tower, together with slight remains of bay 6, sufficient to suggest that the elevation of bay 7 was repeated along the length of the nave. For the rest, both nave arcades have been completely destroyed, and what appear to be survivals are in fact reconstructions. In the north arcade, the base and part of the shaft facing of pier 6 has been reconstructed. Further east in the same arcade, a rubble construction representing the cores of piers 1 and 2, with the arch between them and the lower part of the gallery opening above has been erected for educational purposes. Substantial architectural sculpture remains on the W facade, especially in the portal zone, and on the SW tower.

The cloister is to the south of the nave, and although its arcades are gone there are substantial remains of the monastic buildings. On the east range the chapter house stands south of the transept, then come the dorter and rere-dorter, which extend southward beyond the square of the cloister. The refectory was in the south range, and the west was occupied by cellarage below and the guest house and prior's lodging above. The prior's quarters were at the north end of this range, alongside and immediately SW of the west facade of the church. They consist of a parlour and a cellar on the ground floor, and a chapel and solar above. In the centre of the west range is a two-storey porch. The parlour and chapel are 12thc work, but the west cellar and the solar above it belong to a campaign of c.1500, and the porch was also enlarged about this time. The prior's lodging continued in occupation after the dissolution. Further alterations were made including the installation of fireplaces. Both the chapel and the porch were converted to domestic use. Isolated decorated elements survive in situ on the vestigial Romanesque monastic buildings, principally the parlour and the chapter house. A number of carved fragments are (or were in 1985) displayed in the W range of the cloister.

The Cluniac priory at Castle Acre was founded c. 1089 by William II de Warenne, 2nd Earl of Surrey. Monks were transferred there from Lewes Priory in Sussex, the first Cluniac foundation in England, established by William's father, William I, the 1st earl. The church and cloister were consecrated 1146-48 by William Turbus, Bishop of Norwich. William II endowed the priory with the Norfolk churches of Castle Acre, Methwold, Wickmere and Trunch, and Leaden Roding in Essex. Two of the priory's four dependent cells were 12thc. foundations: Broomholm (f.1113) and Slevesholm (f.1135-54), both in Norfolk. With the abolition of the monasteries at the Reformation, the priory site was acquired by the Duke of Norfolk. Some of its buildings were dismantled and the freestone dispersed and used elsewhere as building material.

Now in the care of English Heritage.

Fernie (2000), 186, comments on the nave pier profiles, noting that they match in responds facing each other under each arch, and that although north and south arcades also match, no base profile is the same as any other in the same arcade. He dates the façade to the 2nd quarter of the 12thc, but McAleer (1984), 471-76, suggests that the façade was not complete at the 1146/48 consecration. The surviving mouldings of the south-west tower indicate that building was ongoing until c. 1160-90.

The decoration of the two elevations of the façade, the internal and the external, corresponds remarkably closely. This is true even when there is some localised discrepancy, as occurs immediately north of the W doorway, both inside and out, where the profile of the arcading differs from anywhere else on the façade ( cf III.3.b.i. and 5.a.i) This confirms that it was the usual practice to build both elevations of a façade simultaneously, even where, or especially where, these were particularly ornate.

Among the Romanesque sculpture fragments on display at the priory (in 1985) is a voussoir (VI.vii above) with a symmetrical floral motif on the soffit. The voussoir is 40cm in length and, as it is decorated at either end with the apex of a right-angle chevron, it is a through-stone, originally part of a free-standing arcade. Assuming that such an arcade would have rested on chamfered imposts, the supporting capitals beneath would have had a top surface of roughly 30cm square, about the right size for single cloister capitals. After the priory buildings were dismantled in the 16thc., voussoirs of the same type, as well as many other carved fragments, found their way to the village of Great Dunham, three miles to the east. There they can be seen reused in great numbers in the house and outbuildings of Rookery Farm, in the garden of the Old Rectory and stored inside the important church c.1100 of St Andrew.

A fragment decorated with syncopated double-disc (VI.vi.1 above) and two 'diabolo' double-cone voussoirs (VI.vi.6 above) at the priory provide intriguing evidence of workshop practice and patterns of patronage in 12thc. Norfolk. The two motifs on these fragments are among those frequently occurring together on a group of decorated doorways in over 20 parish churches, concentrated in a triangle of land lying between the rivers Yare and Waveney in the south-east of the county and NE Suffolk, some 40 miles away from Castle Acre (e.g. St Margaret, Hales, N doorway; All Saints, Thurlton; and in Suffolk, St Andrew, Westhall and St Botolph, North Cove.) This region, the breadbasket of East Anglia, was the most prosperous corner of a wealthy county, populated by large numbers of free men. It was controlled by the Bigods, major post-Conquest landholders in Norfolk like the Warenne family, involved with the foundation of the new cathedral at Norwich and, also like the Warennes, patrons of a Cluniac priory in the county, at Thetford. Examples of the double-disc and double-cone motifs also occur at Norwich Cathedral and Thetford Priory. A single successful sculpture workshop with a distinctive vocabulary of ornament seems, therefore, to have been active in all four corners of the county in the middle decades of the 12thc., working simultaneously for several wealthy patrons, all of whom were presumably equally interested in employing the best sculptors available.