The cache is based on the number π, the ratio of any circle's circumference to its diameter in Euclidean space; its decimal expansion is of course infinite, however for the purpose of finding this cache the first 9 decimals will suffice: π = 3.141592653...
To find the cache your GPS need to be able to use coordinates in degrees.decimals (or you need to be able to convert from degrees.decimals to some other format).
The cache is at:
west: π°
north: p2qx / 2π°
where:
p is the smallest odd prime number
q is the smallest odd prime number not equal to p
x is the square root of a prime number.
There is only one value of x which matches the cache description.
Please do not try to drive motor vehicles to the final location. The place is best accessed walking or cycling, and I would recommend aiming for a point just south of the final location and find it from there. Although you can get to within 4π metres from the cache on a wheelchair, I'm sorry but I haven't been able to place the container somewhere accessible.
Since this cache is based on such an important number, it is fitting that the bus stop mentioned above is served by bus number 42, another important number, for completely different reasons.
There is probably no need for stealth over and above the usual cacher's discreetness; I've stood there for ages looking for a hiding place with "friendly" coordinates, and nobody noticed me, even though a lot of people walked or cycled nearby. However, do remember that the place can be rather busy.
There is a small FTF token (please keep!)
FTF: Grim Fun Scenes - congratulations!
You can validate your puzzle solution with certitude.