INFORMATION:

Portishead is situated on the north Somerset coast with its own small port facility. It sits next door to Avonmouth docks and in WW2 a very big petrochemical works, one of the major petrol works in the south. On the coast across the road from the AA site is Portishead fuel depot which this AA site defended. Portishead Wikipidia.

OS Ref: St441750
You can use the Ordnance Survey 'Get a Map' and follow the instructions. Copy and paste the map reference.