The Round Church at St Andrew the Great (locally known as StAG) is part of the Church of England, and is an attrractive church in the centre of Cambridge
I studied for my undergraduate degree at Christ's College, directly opposite StAG, and thought I'd place a micro here.
The churchyard/garden area has been turned into a city-centre Wildflower garden, and it is near here that I have placed the cache. Access to the cache is on the other side of the church, so you do not have to enter the garden (and probably won't be able to)
The 2-star difficulty reflects the potential issues of finding the cache with lots of people around - this is right in the city centre - and the fact that you'll probably not get a satellite lock next to the church. Please be very careful replacing the cache, as it's in pretty clear sight.
The cache itself is a clear plastic cylinder (a sterile sample container if you must know!). Please make sure that you place the cache back as well as possible such that it isn't too visible to passers-by....