When I was a middle schooler, our military family was stationed in Heidelberg, Germany. It was right around the time of the 70s skateboard craze. I only had a cheap plastic skateboard and skated around the driveway but subscribed to Skateboarder magazine, dreamed of visiting some of these amazing skateboard parks featured in the magazine and doing all of these amazing tricks.
But by the time we moved back to the States, the crazy had ended and most of the parks were closed. I doubt my plastic skateboard would have been able to handle a bowl or ramp anyway.
I ran across this ad on Facebook Marketplace for a miniature skateboard park. I knew they sold mini skateboard toys but never knew it was a full-blown hobby with competitions and elaborate mini skateboard parks!

What is finger boarding? Basically emulating full-sized skateboarding with your fingers and a mini skateboard.
Fingerboarding is a miniature version of skateboarding — people “skate” with their fingers on tiny skateboards. The boards are often made of wood or plastic and have a sandpapery grip tape on top and skateboard graphics underneath. They cost anywhere from a few bucks to more than $100.
– NPR
That is indeed an obscure hobby. Never heard of it before. Never would’ve thought of it. Interesting.