Earthworks still visible on Westleton Heath are said to be the remains of fortifications from the 1173-4 rebellion (Scarfe ref. Gardner). Apart from boundary banks, there is no evidence of earthworks on Westleton Heath, an area of sandy heath. Scarfe can offer no further information (F1 NKB 19-JUL-74). (PastScape)
On Westleton Heath, not two Miles from Dunwich, are Remains of the Barons Fortifications when they besieged that Town. On each Side the Ramparts are two Tumuli, and another East of them. There are supposed, by some, to have been raised in Honour of Personages there interred; but as they are placed at pretty equal Distances, and on the very Summits of Hills, from whence clear Views of the Country round may be taken, I am somewhat inclined to think they were Mounts cast up for that Purpose. (Gardner, 1754)
It is not now really possible to read the medieval landscape which has been altered by Second World War practice trenches and anti-invasion works and is part under woodland. The trig point at given map reference is the highest land on the heath but probably not the site of Gardner's tumuli. Burial mounds are often place on high land to be visible so Gardner's logic is weak. Most probably what Gardner saw were pre-historic earthworks but this does not mean these were not temporally adapted as fieldworks in the C12. Certainly the mounds would have been used as viewing platforms.