The Black Hole is a water slide at the Bad 1 waterpark in Bremerhaven, Germany. It's an older slide that's been retrofitted with a ton of different LEDs to make riders feel like they're traveling through star fields and a black hole. I've got the feeling traveling through an actual black hole probably wouldn't be so pleasant. I imagine that would be more like hell. Which means there would almost certainly still be little kids shitting in the wave pool.
Keep going for a POV ride so you can pretend like you're there.
Thanks to hairless, who could easily set the record for the fastest ride down that thing on account of an incredibly smooth body.