Visiting Sandland for Crazy Homemade Tunnels and Monorail (YouTube) (2020)

In Upper Midwest: Minnesota on the Wisconsin side http://tunnelcity.com/ https://www.facebook.com/pages/category/Just-for-fun/Sandlan...

This place looks like a hidden social treasure in the making. Lots of engineering and hacking going on here. One of these days I am going to bring my lidars up to Sandland to get point clouds.