The One Ring: Fellowship of the New Alliance
Foul marshes surround Dol Guldur on three sides. The easiest way to cross these swamps is via the Fenbridge, a snaking line of orc-built crossings that run from hillock to hillock, and the only way onto the Fenbridge is through Fenbridge Castle. Fenbridge Castle is a sprawling, unplanned fortress; it started as a mere gatehouse, but has had innumerable other towers and bastions added on over the years. Fenbridge once supplied food and manpower to Dol Guldur.