The Baigong Pipes

This remote area in China is said to be inhospitable to human life, but somehow there exist three mysterious triangular openings at the top of a mountain that contains ancient iron pipes that are said to from Chinese dynasties. The pipes run deep down the mountain that has its opening in a saltwater lake nearby. You must be thinking, what’s so strange about these iron pipes? According to archaeological experts, the pipes are clear of debris and were meant for some kind of purpose ( obviously), however, even to today, the archaeologists don’t know the reason behind it.
Some theories involve using these pipes for ancient astronomy lab. Could be or could be not. We can’t say for sure.