North of the Priory, in Southover High Street opposite Southover Grange, is the site of the Hospital of St James founded by William de Warenne, the second Earl (d.1138), as a hospital for 24 elderly or infirm brothers and sisters and for pilgrims and the sick. It was maintained by Lewes Priory and survived the dissolution. The great infirmary hall has disappeared and only part of the chancel of the chapel remains. 18th century prints show this converted to a cottage.
The remains comprise Scheduled Ancient Monument No 253 for which there is an official description and a definitive site map.
The structure is included on the Statutory List of Buildings of Special Architectural or Historic Interest Grade II. Read the official entry.