The A3201 comprises the short Marshalsea Road in The Borough area of Southwark in central London.
The road starts at traffic lights on the A300 Southwark Bridge Road and heads in a roughly eastward direction along a largely uninteresting road. It soon ends at a second set of traffic lights on the A3 Borough High Street opposite the church of St George the Martyr and Borough tube station. Straight on is the start of the A2.