Crossing the Gorge is the Bridge of Skulls. Around it and below it are many rocks, and it stands over at least one pool of water. Nearby is Westwatch-by-the-Bridge, an unoccupied castle of the Night's Watch. The Milkwater appears to flow through the Gorge to the Bay of Ice.
A Game of Thrones
A Storm of Swords
A Dance with Dragons
The commander of the Shadow Tower, Ser Denys Mallister, writes to Castle Black to report sightings of fires in the night north of the Gorge. Denys believes wildlings are amassing to force the Bridge of Skulls once more.