Anyone know where the teleporter in Aldea is located? I heard rumours about it being in the basement and even blew up an oil drum of sorts in the SE corner which revealed a hidden room but there doesn't appear to be anything there. What am I not seeing?

You are close. At the north of the Aldea Basement is a part that is supposed to look like a labratory (yellow-ish walls). When you enter this section through the door leading there, there is oilbarrel at the right end of the corridor, although it's placed in way you can't see it. So, either auto-fire blind to the right corner until it goes boom, or use explosives. The wall should break and reveal a hidden room. Inside this room, at the top-wall, there is a switch. Use the switch and another door will open. Inside this second room are the teleporters.
If you're interested in this easter-eggs, also take a look in storage room with wood-crates at Tixa Basement. There is another one.