The car park in North Road is situated past the gym entrance and turning left at the traffic lights (Turning right if coming from southend). Once parked make your way back to the traffic lights.
Once back at the traffic lights you will see the cricketers pub; if you look slightly to the right you will see the gate. Make your way over and walk through the gate.
Look for the stairs on other side of the pub car park and walk up to the entrance.