Note: Ancient town located at the point where the River Thet meets the Little Ouse. 31 miles SW of Norwich, this town was the seat of kings of East Anglia. It is located in an area known as Breckland that was once a great expanse of sandy heath; today the area is planted with pine forests and little open heath remains. Although Thetford lost most of its political power in the early Middle Ages, remains of its impressive fortifications exist. Castle Hill, an earthwork on the town's eastern outskirts, is the largest mound in East Anglia at 81 feet high and almost 1000 feet around the base. A Norman castle at Castle Hill was supposedly torn down in 1173. The Normans made Thetford into a major religious center; it was the seat of the bishops of East Anglia in the 11th century. The noted remains of a Cluniac priory founded ca. 1104 are still here; St. Cuthbert's is the only medieval church of Thetford still in use. Thetford was also a royal retreat with the King's House (now home to the Thetford Council) as a hunting lodge used into the 17th century. There was an attempt in the 19th century to make Thetford, with its mineral springs, into a spa town. Thomas Paine was born here in 1737.