Coin stacking.

Never heard of it..? Well, here’s the site

Gets crazier…

Apparently much of this is induced by boredom from studying.

This reminds me of when I was younger, how we used to make gigantic houses of cards. But it was more like housing estates, because it would spread over a big area but we weren’t precise enough to be able to build upwards. Occasionally we would manage a bit of a second storey but it was difficult.