The Juran Mountains is the area in the second Old republic trailer where Caprain Jace Malcom led Havoc Squads ambush against Darth Malgus, with the help of Jedi Satele Shan. It looks nothing like the trailer (at least that parts I saw).
This area has House Alde in the middle, they are aligned with House Organa. Also in this area is a Ulgo Fortress, and House Rist, which is alined with House Ulgo.
There are 2 sith Inquisitor mission in this area. The first one (The Secrets of the Jedi) is to enter by force in to House Alde library and find out anything you can about Nomar Organa to see if you can lore him back to Alderann, you find out he was almost married once to Rehanna Rist, who now is the head of the Rist house. This starts the second quest “A woman Scorned”. You’ll have to enter house Rist and fight your way to her, and it takes a pretty long time to get to her. When you get to her and defeat her she will call Nomar Organa asking him to come to Alderaan and meet her in their secret meeting place.
For the Empire side quest mostly deal with Ulgo Fortress. And that pretty much it (that stories were not that interesting).
And now for more pretty picture of The Juran Mountains…. OOO and flying Whale mounts for the win