Built by Jelle’s Marble Runs, Marblopolis is a massive marble-run amusement park featuring 30 attractions: loops, funnels, jumps, halfpipes, and more! All of these are connected by nearly a quarter mile of track, with room for up to 400 tiny thrill-seekers at once.

If you ever find yourself near Tante Hannie Gift Shop (Nijmegen, Netherlands,) you can even see this ridiculous masterpiece in person (until summer 2026).

[Via BIS]