Priory of Castle Acre is relevant. The church had an internal length of 128m (420 feet) from west door to chancel apse, with an internal vault height of 28m (93 feet) at the altar and 32m (105 feet) at the crossing. This was the largest church in Sussex, being longer than Chichester Cathedral including its Lady Chapel, and is comparable in scale to the original form of Ely Cathedral or the surviving form of Lichfield Cathedral. Priory buildings These comprised the cloister and chapter house directly south of the church and the dorter, reredorter, frater and infirmary to south and east, of which sections survive above ground, as well as the Prior's lodging and entrance gates to the west of which fragments also survive. The dove house to the south-west was a large building that survived until the early nineteenth century. It is reasonable to assume a pattern of bakeries, fish ponds and other food production and storage buildings in this area of a type and layout identified at Castle Acre and other English Cluniac houses. Subterranean cisterns and drainage courses as well as fresh water conduits have been identified by excavation. Hospitium, now St John the Baptist, Southover This church incorporates the original hospitium. The twelfth-century nave arcade, with short drum piers and un-moulded arches perhaps divided the men's from the women's ward. The neo-Norman south chapel of 1847 houses the bones of William and Gundrada de Warenne unearthed in two lead cists by railway navvies in 1845 constructing the Brighton to Lewes railway through the site of the Priory chapter house. On the floor of the chapel lies the original black Tournai marble tombstone from the Priory carved to the memory of Gundrada that had been incorporated into a Tudor period memorial in the church of St Margaret, Isfield. Precinct walls The most extensive surviving mediaeval structures are the precinct walls along the north (140 metres) and east (170 metres) sides of the Dripping Pan. Lengths also survive down Cockshut Road bounding the west side of the precinct. Significant secondary walls within the great precinct sub divide the land, notably the south wall of the Dripping Pan. The precinct walls have otherwise generally been removed for housing development, the railway and a car park near the Mount. Fragments of the Great Gate (circa. 1200 AD) exist in a rearranged form adjacent to the east end of St John's