The Western Outworks occupies the Western most part of the Heights' defences and is joined to the Citadel by a bridge. Barrack huts on the surface remain in good condition, both internally and externally and are within the DIRC perimeter. Outside of the perimeter, a row of Haxo casemates with Unmarried Soldiers' Quarters behind and two large sets of casemated barracks at ditch level are in a dilapidated state, and a large double caponnier has been buried with no current access.
There is no public access to the Citadel, but I worked there some years ago, and was fortunate enough to be able to access some of the main parts.
The Outer Bastion.
Update May 2011: I attended a visit with the Fortress Study Group to the Citadel tunnels, including some recently opened parts of the Outer Bastion and the Counterscarp galleries. The tunnels are mainly in excellent condition, with some original doors remaining in situ. Unfortunately, due to security restrictions, cameras weren't allowed.
The Citadel's Outer, Centre and Inner Bastions
One of the Casemates , the floor between has been removed