The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at You Know, That Thing Where.
Cool Gate when it's an entryway of some sort
There's no real dedicated index (good project if you're looking for one, to be honest), but there's a few closely related indexes to look at:
Otherworld Tropes collects a bunch of these as part of gathering Another Dimension-type tropes. Interdimensional Travel Device, Portal Crossroad World, Bazaar of the Bizarre, and Inn Between the Worlds are a few of the ones that come to mind from there.
You might also look at Teleportation Tropes, which has a lot of the more scifi-flavor tropes that get involved here, like Teleporter Accident, Random Transportation and Subspace or Hyperspace
Edited by Scorpion451
Thanks Scorpion, I'm writing a story and I wanted a list of examples of all the ways to enter a new world so that I could attempt to come up with a new way of doing it for the screen.
How would I find a list of all the ways to enter another world like the Wizard of Oz and Alice in Wonderland etc? Thanks.