This is part of a series of geocaches set by Hersham Guides, this one set by the Polar Bear Patrol.
You are looking for a small red tupperware box, watch out for muggles at this very busy location. UTMOST SLEATH required for this one. Don't give the game away. Try and hide the cache well again with some fallen leaves once you have located it.
Should be big enough for small trackables and some swaps.
Again, this is a high traffic area so be careful.