This is a cracker ... Heatherwood Hospital is just across the road from Ascot racecourse, on the big roundabout. Strictly speaking, you should really be a patient, or visiting one, to gain access, but they'll spank you for the parking fee regardless.
Inside the hospital, inside a tiny quadrangle, is a fair sized bowl barrow, probably late Bronze age. There's a little sign by it, but otherwise absolutely no acknowledgement of it's existence. Even the size of the space allocated to it demonstrates the begrudging nature of it's survival ...
'...and in the grounds of Heatherwood Hospital at Ascot, where the remaining barrow was formerly one of a group of four. Excavation of the Heatherwood barrow in 1973 dated it to circa 1800BC.'