This, by far, looks to be the easiest implementation, especially if you have an aura to denote the boundaries for the teleportation.
And this is also a solution I've used for pretty much exactly the same system (random areas). It works very well as far as I've tested it.
I'm curious how many similaries there might be, then. Mind telling me if you use random areas as a means of travelling between regions or perhaps put a greater emphasis on it and focus whole gameplay around it, akin to Infinite Dungeons?