The earthworks are certainly from pre Norman times, maybe Iron Age. It would seem there maybe evidence at least from early Saxon round houses. There are fairly substantial ringworks mostly complete, often the main ditch is in water, fed by a nearby pond and stream. The earth works are up to 20 foot high especially in the south section. The walls of course would have been a wooden palisade so no survival from any period.

With the invasion of the Normans it seem the castle was taken over and modified. Towers were built in the corners as can be seen by raised sections.  An additional compound built to the west giving the site an outline of a motte and bailey castle. However there is no bailey mound. The entrance seems to be  in the south west corner. Access was probably by a bridge with a draw bridge. The palisade wall may have been roofed. There is evidence of rectangular outlines of buildings. The North west tower outline is larger than the others and on a higher mound.  There is a breach of the earthworks to the outer bailey area presumably for access. It would have overlooked the valley. Not of great significance, the castle was probably abandoned within 50-100 years. Pottery has been found.

The Brenchley area is on the edge of the past Wealden iron producing region (pre industrial revolution) It is known that the castle location was used for commercial activities after the 12th century.  Iron slag and cinders have been found. Three possible quarries for iron workings are found locally. The south of the earth works are significantly wider and could be a quarry (water filled) with the waste piled behind. Immediately to the south west a quarry, later dammed up (hammer pond pond bay?) which is possibly an upper pound water supply for a hammer mill. Another quarry lies to the south east.  A lost sunken lane can be found going towards the castle. The outer earthwork has been breached to the North East maybe for access to the works.