Just found The Foul Lair. In the desolate sands there is a random event where you meet a man that tells of his brother dying by using an acient device to enter a set of ruins. Normally a portal will not spawn. Instead you get some elites that spawn. If you do by chance get the foul lair to spawn you can enter. The dungeon is very small. There are a bunch of chickens all over the place. There is only one mob to kill. A pig that drops a bunch of loot.
Ha thought this was strange glad I was able to get the portal on my first time finding this haha greasy pig was kinda a funny suprise :P and I killed all the chickens thinking maybe a big one would come out all pissed aka kinda Zelda style :P buuut nope :( aha.