dont know where to put this ancient engeneering marvel caves video, if anyone knows its suitable thread plz move it there.....
Barabar caves in bihar date back at the very least 260 BC, build by ajivika's....The measurements found in the caves suggest the use of the meter, which was not invented until much later in history. View: https://youtu.be/8YBFjn5Gv_Y?si=2EFO6U39fZ9EBtJ1