The few times I have been there I don't remember seeing any litter. It is a great location for a normal event though, great views, lots of parking, and public conveniences.
This way, a few parts of disused canals are looking shabby. A part of the Thames and Severn, not far from where I am holding my event on Saturday, I was quite upset the other day to see someone had fly tipped a lot of junk into the canal. And the path along another disused stretch of canal between Cirencester industrial estate and Siddington Village often has a lot of litter, and waste packaging bits which I guess blow over from the nearby units.
Are there any similar stretches of old waterways / railway lines up your way that need attention?