The ancient Chinese sure know how to amaze.
The Maijishan Grottoes is a 190+ man-made cave system 45 kilometres southeast of of Tianshui city, Gansu province. It is 142 miles above ground and covers 215 square kilometres. It is distinguished by its beautiful clay in stone sculptures.
It’s name is derived from its shape: “wheat stack”. Construction started in 384, and continued for 1600 years.
How the heck did they do that? Amazing.