Access may be possible through an entrance cut into the wood, but it's often very overgrown and it's usually best to duck under the barrier and walk along the edge of the field before heading into the wood at the first real opportunity where a path of sorts is clear. During summer it may be hard going through nettles and with not much of a path - these footpaths are no longer regularly trod.
The Airfield:
RAF Thorpe Abbotts was built in 1942 and handed over to the USAF 8th Air Force in 1943. It operated as a base for the B17 heavy bombers of the 100th Bombardment Group until 1945.
Disused airfields like this dot East Anglia. Browsing an OS map will inevitably lead to the discovery of a set of tracks in a diamond or star shape - the cartographical reminder that the skies were once full of planes. Most have fallen back into agricultural use, although many retain small memorials or museums.
At Thorpe Abbotts the 100th Bombardment Group Memorial Museum operates at weekends, bank holidays and summer Wednesdays at the old control tower to the north of the airfield. You can see it from the cache site. It's free to visit and has an interesting web site as well. There's an excellent muticache from 2004 close by which requires some internet research into the group to find the final coordinates.
The cache is just inside the southern perimeter of the airfield. The road near it was originally part of the field and areas of hardstanding and perimeter marker posts are visible on the southern edge of the wood next to the cache. The woods further south still contain remains of barracks and support service buildings which spread as far south as the A143.
The Cache:
The cache is a lock and lock container which is on the larger side of small. Although the footpath isn't much used, it would be appreciated if you could cover it appropriately to avoid detection. The easiest access is from the south: the footpath is not signposted from the roadway but an entrance way may be cut into the wall of undergrowth. If it is then use that - the first few metres are a bit tricky but after that the wood opens up; otherwise use the field edge. The footpath continues to the east through the trees.
Caution: nettles are likly to abound in areas around the cache site. Shorts and sandals would be ill advised. There may also be a bit of ditch crossing necessary if you walk all the way along the field edge.