Lewes was the county town of Sussex before the county was divided in 1974, and is now the county town of East Sussex. It stands on the River Ouse, 6 miles NE of Brighton. The ruins of the priory are in Southover, on the SE edge of the town and are now bisected by the East Coastway rail line. Most of the priory site is occupied by Priory Park, on the S of the railway. The priory constructed by William de Warenne consisted of the great church with its cloister to the S bounded by the refectory on the S range. S of this stood the rere-dorter, later extended with a new block to the E, and the Infirmary. The site was bounded on its southern edge by the Cockshut stream, a tributary of the Ouse which provided the water supply. The Infirmary chapel, built to the S of the eastern arm of the great church on a slightly different axis, is assumed to be the first Cluniac church on the site. Its postion allows the visitor to locate the position of the great church itself, of which there are no standing remains except for the S wall of the SW tower, lying as it does below the railway line and the privately-owned land to the N of it. When the railway was built in 1846 the foundations of the church were revealed, enabling St John Hope and Breakspear to produce a plan (Hope 1884). The best description of the standing remains will be found in VCH (1940).

The only sculptural remains in Priory Park are reused in the Prospect Tower, a cylindrical, battlemented tower built at the W end of the park. Carved and moulded voussoirs from the priory are incorporated into a doorway and two of the window arches.

The rape and town of Lewes were given to William de Warenne shortly after the Conquest, and he and his wife Gundrada founded a monastery there under the direction of Lanzo and three other monks from Cluny in 1070. Their first church was that of St Pancras, recently rebuilt in stone by William de Warenne, which was to become the infirmary chapel of the priory. The original endowment included this church and the land surrounding it, and land at Falmer and Balmer as well as Wiiliam's Norfolk manor of Walton. This was enough to support 10 monks, but the monastery grew through the gifts of William and his successors. The new great church, built on the model of the mother house (Cluny III) was dedicated in c.1095, also to St Pancras. The priory was formally surrendered to the Crown in November 1537, when the prior Robert Crowham, received a pension and a prebend at Lincoln cathedral, and the 23 monks and 80 servants were pensioned off. The priory and all its lands were granted to Thomas Cromwee, Earl of Essex.

Other carved stones from the priory are to be seen in gardens and built into walls around the town and the local area. Churches outside Lewes with reused priory stones are at Beddingham, Ringmer and Rodmell, but the majority of carved stones are held in the Anne of Cleves House museum, Southover. Of the stones in the SE doorway arch here, the lozenge design (e.g. voussoir 3) and the paired medallions (voussoir 4) are both found at Beddingham.