It is a natural limestone plateau, on the edge of a wide band of Oolitic Limestone.
The geological deposits, shown in Figure 5, are mostly from the Jurassic period, save for a pocket of older Triassic rocks in the NW corner.
The “Liassic” is not nowadays considered to be a separate period, but part of the Lower Jurassic.
“Cadbury Camp” is in the north of the county, near the Bristol Channel, close to the village of Tickenham, and eight miles west of Bristol.This essay is about “Cadbury Castle” which is fifty miles further to the south of “Cadbury Camp”, and close to the village of South Cadbury, and 7 miles to the NE of Yeovil.Recesses on either side of some passages indicate that two doors were meant to fold back into them when open, and when closed they would rest against a blocking stone, whose base was firmly buried beneath the road surface.” (Ref F) The more hillforts are studied by excavation, the more impressive the technology of our ancestors appears.They chose high places to fortify, and put in a great deal of effort in creating multiple ramparts (11), wooden palisades, stone revetments, complex entrances, guard chambers and gates.Nevertheless, there are other ramparts, (9) whose steepness gives some idea of the defensibility of the original fort.
Entrances to hillforts were extremely variable, but carefully constructed, because these were the weakest part of the defensive system, as there was continual coming and going.To add to the confusion, this second hillfort is sometimes known as “South Cadbury Camp” or “South Cadbury Castle”.Rounding off the confusion, there is also a hillfort in the next county, of Devon, called “Cadbury Castle” close to the village of Bickleigh, about six miles NE of Plymouth.(Ref D) The ramparts of the hillfort enclose an area of 7.28 hectares (18.0 acres) which is quite heavily covered by deciduous trees, as shown in Figure 1.These may make it look more picturesque, but give a false impression of the original fort, which would have been kept clear of all trees for defensive reasons.Cadbury Castle is in the region of south Somerset, a gently rolling countryside, without any great or dramatic hills, except for the North Dorset Downs, in the next county, as the map in Figure 3 shows.