Okay, so this is a work in progress and I'll update it sometime in the future. To get this to work and play this map, you have to play Modded Minecraft with the Immersive Portals mod installed. If you don't, this map won't work.

I Have 5 Things Done and one work and progress one.

This map includes an infinite tunnel, an infinite rainbow drop, a snow globe in a snow globe in a snow globe in a snow globe IN A SNOW GLOBE.
(It also has the infinite staircase from Super Mario 64)

If anyone has any ideas on what else to add just comment!