Silken Paths

The Silken Paths are a massive network of spider webs over a chasm that stretches for miles across the Underdark. These paths are ever-changing as old webs rot and fall away while new ones are spun by the countless giant spiders that inhabit the area. Traversing these webs is the only way through this particular section of the Underdark; there are no other foot paths, faerzress fills too much of the area to make teleportation magic safe, and the webs fill the area so completely that even creatures capable of flight cannot avoid them.
The remains of creatures who failed to leave the Silken Paths alive litter these webs, often cocooned and drained of fluids. Only those who worship Lolth, the Spider Queen, can traverse the webs undisturbed by the spiders that call it home. Even then, there are many other dangers in the area. Hungry stirges, darkmantles, and other predators compete with the spiders for prey when not devouring each other. A misplaced step or broken web can send one falling down into the chasm below, falling far enough that any others nearby won't even hear them hit the bottom.
The cliffsides at the ends of tunnels overlooking the Silken Paths are frequently attended by ettercaps, who build hovels at these sites and use various sections of the Silken Paths as giant spider farms for their drow masters.

Journey Into the Underdark Arc

The Thaig Expedition crossed the Silken Paths early into the expedition into the Underdark, battling giant spiders, darkmantles, and a spider-like OoPA as they made their way across. They also saved the kuo-toa Mmottukuu from the aforementioned spiders webs while here, gaining one of their first allies in the Underdark.

Type

Gorge / Rift