Danbi Bridge was the only way for the emperor to get to the Hall of Prayer for Good Harvests. The central path was reserved for divine gods, the path on the left was reserved for the emperor and court officials used the path on the right
You may ask, 'it's obviously a road, so why is it called a bridge?' The bridge is four meters above ground, and a tunnel passes under the path, so it's correct to call it a bridge.
The tunnel is called Jin Sheng Gate, meaning the way for sacrifices. Cows and sheep were herded into the ButcheryPavilionto be sacrificed. Of course these animals weren't allowed to walk on the sacred Danbi Bridge, so the tunnel was built for them, creating China's first cloverleaf junction. The tunnel is also called the Gate of Hell, and no one dares go near it.