In the underground lake, there is a portal, I tried it, but couldn't get it to take me anywhere. Also, there is another in Khelben's Tower, the part you can access from Waterdeep, w/out going through all the teleporter maze stuff. Wonder where they go, and when they will take you there? Note: don't really think this is a spoiler, as I have no clue if these portals even work, or ever will. Could be Halaster just pulling our chains.