From the motorway network:

From the M5 north or M5 South, take the M4 East for one junction to the M32.

From the M4 take the M32 (signposted to Central Bristol)

Follow the M32 past all three junctions right to the city centre. At the first set of traffic lights (by Staples) choose the left lane (but do not turn left off the main road). When the main road splits take the left branch and follow this road until you see a slip road on the left leading up to a roundabout. Take this slip road and turn left at the traffic lights on the roundabout into Old Market Street.

At the next traffic lights (at the junction with Midland Road) you have to turn left because of the one-way system. Get into the right-hand lane of this road and follow it round to the right. When the road splits, take the right fork and stay in the right-hand lane. Turn right again at the traffic lights and you are now in West Street. Park wherever you can - there may be on-street parking in some of the side roads: use your own judgement. The Old Castle Green is the second building in Gloucester Lane (on the right of West Street).

Journey time from the M4 approximately 10 minutes depending on traffic conditions.