These two walls (east and west) are the remains of a machine gun range built with bricks from a company that closed in 1930, indicating they were built around World War I. The two walls are slightly different, the eastern one being reinforced with 12.5mm thick iron sheeting, suggesting this was a later wall.
Did you know: The eastern wall has graffiti from 1941, showing it had fallen into disuse by World War II. Can you spot it?