The ruins of the 14th century priory church of the Canons of the Holy Sepulchre (sometimes known as St Sepulchres Priory). The church is the only surviving remain in England of this Augustinan order. The priory was established around 1139 on the south bank of the Little Ouse river.
The priory was dissolved by Henry VIII in 1536, and the church was used for a time as a barn. The building is rectangular, with no aisles, and is 24 metres long by 10 metres wide. The walls stand to 6 metres high, and are built of flint rubble dressed with ashlar. In the east end of the nave are the remains of a grotto created when a pleasure garden was built on this site in the 19th century. Excavations have revealed that the church stands upon remains of the old Saxon town of Thetford.

The Church of the Holy Sepulchre is located almost directly opposite the remains of Thetford Priory, across the Little Ouse river.