The B477 is a short, albeit narrow, B-road in northeast Berkshire.
It starts at Hare Hatch on the A4, a few feet west of the junction with the A3032 for Twyford.
The road narrows to become S1 almost immediately and zigzags in a vaguely northwesterly direction. It traverses the flat Mumbery Hill and enters Wargrave. It ends at a set of traffic lights on the equally narrow A321 High Street, without ever having regained white lines down the middle of the road except to aid at junctions and crossings.