I will be archiving this cache on 1 July. The cycle underpass where this cache has been placed will be closed from July until February 2015 due to roadworks for the busway extension to the new Chesterton station. I may put a replacement cache in a similar location when things reopen
There are more caches along the St Ives to Cambridge guided busway than I can count. This is definitely the last!
It is placed near the short tunnel on the cycle and footpath adjacent to the road. This was built when the railway was still in operation to provide a means of crossing the track even when the level crossing was down. (There are other similar examples on the lines north of Cambridge.)
The cache is a nano, but should be easy to find. It is not accessible from road level. It is also not in or near any of the electrical wiring, and well clear of the ground: you will not have to rummage.
Please replace carefully to prevent it being muggled.