The highway originally built by the Romans, which we know as Watling Street or more recently the A5 trunk road, rises steeply from the junction with Spur Road, Edgware, to the summit of Brockley Hill, climbing some 70m in a distance of about 1400 metres. The descent from the summit to Elstree Hill Roundabout about 600m to the North drops about 30m.

The area is associated with the archaeological site called Sulloniacis.

Its most prominent building is the Royal National Orthopaedic Hospital.

Brockley Hill is the eastern arm of a long hill centred on Stanmore. The top of the hill is capped with Stanmore Gravel, which is the remnant of a layer of gravel laid down by a river system pre-dating the Thames. Under the gravel are layers of sand, silt and clay about 15 metres thick known as the Claygate Beds. Below this is London Clay about 70 metres thick.