A puzzle for scientists was found in Shelbyville, Illinois, US | GUIDELESS through the night - and out of it💡

A puzzle for scientists was found in Shelbyville, Illinois, USA. The town was founded in 1827, which is very recent by historical standards. How the city ended up 4-5 meters in the ground is a mystery.
https://redd.it/rigr2r
@r_interestingasfuck