Nothing specific, I’m hoping for the opposite. Something most people either aren’t familiar with and/or just something you enjoy.
The website shows the depth of the sea. It takes a really long time to get to the bottom
Here’s the same thing for space!
If the Moon Were Only 1 Pixel, A Tediously Accurate Map of the Solar System
https://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html
I really wish Flash was still a thing, my favourite way to waste time was addictinggames or newgrounds back in the day
https://neal.fun/password-game/
Starts off fairly easy, but quickly just becomes ridiculous. I’ve only gotten about 14 steps in so far.
Pointless sites is a great conglomeration. I think there’s one called sand spiel? It’s a fun physics toy. Also can’t go wrong with Simon Tatham’s puzzle collection.