Dubbed as “the Thirteen Levels”, the old copper refinery is also called “the Potala Palace of Mountain Mines” as it looks like a beautiful abandoned palace far away. The parking lot at ShueiNanDongand the lookout pavilion in Changren community provide an incredible view. Music videos of famous songs are shot here, too. The building has the longest gas pipe in the world, which is 2 kilometers in length and 2 meter in diameter. Due to possible fatal accidents, visitors are not permitted to enter the pipe.