A Thread of Sky is located at the backside of Dagang Mountain where Gangshan and Tianliao joins. From the backside trail of Chaoyuan Temple, it takes about 15 minutes to get to the destination. The trees provide shade and the air is fresh along the way. It was alleged that a north-south crack appeared on the back of Dagang Mountain due to an earthquake in the 36th year of Emperor Yongli’s reign in the Ming Dynasty (1682), forming a mountain gully. When one looks up at the sky from the gully, only a thread of sky comes into view; this place was thus named. The gully maintains its original natural beauty. Traces of stalactites can be seen on the wall. Baletes grow crookedly near the entrance.