A magazine associated to the Machynys rifle ranges (NPRN 413307) located between the two target areas (NPRNs 420182-3) . It is a ruined rectangular building measuring 5m (N-S) by 4.8m (27 ft x 16 ft) within mortared rubble walls 0.6m thick. There is an entrance gap in the north wall. The interior of the building is strewn with rubble but walls survive to about 1m high except at the north-west corner where a pillar of masonry is 2.9m high.
The building is portrayed as a magazine only on the First Edition Ordnance Survey six-inch map (1884) though it continued to be shown as a standing building on later editions. As the ranges developed it may also have functioned as a control room.

David Leighton, RCAHMW, 20 June 2014