English Heritage says about the Camp:
Bullsdown, a triple plateau entrenchment on a very low and gently rounded hill about 20' above the surrounding country. It is an irregular oval following the brow of the hill. The enclosed area occupies 10 acres and the earthworks themselves another 10.
The remarkable feature is the broad platform c.29' wide, which forms the summit of the middle rampart throughout its length. It is slightly worn down in the middle and is in part
occupied by a farm track.
The banks and ditches are fairly sharp at any rate on the southern side. On the highest ground at the NE corner, the ramparts have been completely cut away for c. 100 yds and can only
just be traced: the original entrance may have been here. The Entrance at the S.W. is obviously modern. There is no trace of walls at any point, nor of outworks.
Brooks and swampy ground surround this earthwork on three sides - about 1/4 mile off on the N. and E., and c. 150 yards on the S. It is occupied by an oak wood with clumps of fir trees and very thick undergrowth, and in the natural state the ground around would be
thick forest.

The earthwork on Bull's Down is an I.A. plateau-fort: Mr. G. C. Boon,
former assistant director of Reading Museum, has stated in coversation that he thinks it may perhaps be the oppidum which preceeded the Belgic settlement 3 miles away at Silchester. It is situated at 200-220' above sea level at the northern edge of a plateau on a heavy clay
soil and is so heavily overgrown that it has never been thoroughly examined and its original entrance has escaped notice. On the east the ground is level and the ramparts consist of an inner bank (mutilated by the construction of a boundary bank at its inner edge), ditch, a wide berm with a bank on its outer lip, a deep ditch and an outer bank. On the west, however, the natural slope falls over 3m. across the ramparts and here the defences consist of a wide terrace
with upper and lower scarps, made by levelling the natural slope, and a comparatively feeble ditch and outer bank. Around the surviving part of the northern side there is an inner bank above the terrace. There is no other earthwork of this type in Hampshire but its profiles, though not its plan, are very similar to those of the earthworks in Hammer Wood, Sussex.

The only surviving original entrance is at the north-west. It is a simple gap with the outer bank inturned across the line of the ditch: a circular mound in the centre of a gap may, or may not, be an original feature. The modern boundary banks, which run around the inside and the outside of the ramparts, are not interrupted at this entrance.
The interior of the earthwork is woodland an no occupation debris was
found.

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