Hi!
I am new and thought I would start off with a post about something I found a while ago.
I have recently stumbled upon a place that appears on one's map as Quel'thalas - an unselectable area on thet World Map before TBC (even though you don't need TBC to get here).
If you go to Tirisfal Glades at the coastline north of SM, there is just open sea. But, if you continue northwest along the coastline for a while (I suggest bringing some swim speed pots) you will come to some Night Elf ruins - nothing special here, but it looks cool.
BUT the cool thing in this is if you have TBC installed and you have a look at the World Map, then you will find that you are swimming in the Ghostlands. Therefore, you are swimming on the pre-TBC coastline.
Enjoy