Photo Charles Taylor

Part of the Western Heights defences which also comprise The Citadel and Drop Redoubt, St Martin's Battery and Citadel Batteries as well as the Grand Shaft Stairs.

The North Centre Bastion dating from 1804 to 1810 is very overgrown but still extremely impressive in its size. The North Entrance was built in the 1860's. It is in poor condition, the bridge having almost collapsed, and is very overgrown.

Both sites are fenced off and can only be viewed from the outside.