Thetford Castle Hill.
Thetford Castle Hill is an enormous mound, partly sunk into a deep surrounding ditch, and two sets of ramparts. The hill itself is a Norman motte earthwork, erected during the 11th century following the Norman conquest. A wooden tower may, or may not have, been built on top of the motte. The castle guarded the Little Ouse, and an important river crossing, at what is now Nuns Bridges. The medieval market was created close to the castle at Old Market Street.
The earth ramparts of the castle defences are believe to have been built up on top of much earlier defensive ramparts, that belonged to an Iron Age hillfort, dated to somewhere around 400 BC to 100 BC.
Today the site is part of a large green area known as Castle Park. Childrens play areas have been layed out close to the ramparts.
