Thousands of feet up a mountain with no road, CARVED into solid rock...is a door.

• There’s a lot of speculation about it being a nuclear shelter, but that is unlikely, as nuclear shelters typically require thick, reinforced walls and are often built underground. This structure, with its visible stonework and seemingly less robust construction, appears more suited for historical or religious use rather than modern military or survival purposes.

• Given its location in Jinan, Shandong, this could be a historical site, possibly used as a secluded spot for meditation or small-scale habitation. These types of hermit structures are significant in many Asian cultures as spiritual retreats.

"Those look like blast doors. With handles on the outside of them which means they were meant to be accessed from the outside. This is most likely a storage container for TNT, or other blast ordinance for mining the mountain. Its high up and away from civilization but at one point its location was convenient but as the mining became deeper into earth, it was forgotten and neglected even it's undersides blasted away condemning it. No use in wasting ordinance because it is inaccessible now."

Aegean Girl
(X.com)

SOURCE
Science girl