Located about 10 miles southeast from Waterdeep, where the Trade Way crosses the Dessarin River. The bridge is after the wizard Zund who created it about 80 winters ago when construction of the Great Trade Way was completed (to Waterdeep at least).
There is a Waterdeep guard post of highly trained warriors and customs officers commanded by Sai Halloran, and his sword Helmstooth, whose loyalty knows no bounds and his lieutenant Wendel who is legendary for his vocal prowess and his ability for catching arrows and deflecting bolts. The warded guardpost has stone edifice and is fortified with three towers. Additionally, the guardpost has three griffon mounts at its disposal should reinforcements be necessary. There is also a campground, a water pump and a sign warning passers-by not to enter the Rat Hills at their own peril.
The most popular and most fantastic tale regarding the Zundbridge is; don't magically trouble the bridge with magic or subterfuge, it's rumored to be a stone golem of some sort. As for size, it is a squat and massive construction stretching five-hundred yards across the Dessarian River gorge and is twenty-five feet across.