The Outpost itself was originally taken and held by former Commander of Serpent's Fang, Ardiniss, before he was killed by Chaos soldiers. Remains of Order followers can be found strewn through the ruins, along with Chaotic Wildmen, who have taken over the Outpost since it fell.
The Outpost can be found south-west of Serpent's Fang, and is reached by entering the Serpent ruins which form its corridors.
One of the magic Orbs (red) can be found sealed beneath the Abandoned Outpost, where it was placed by Ardiniss to protect it. The sealed chamber which contains it can be accessed by using a Lightning Whip to unlock the seals.
Another notable item found within in the Outpost is Loriel's Gift, a magic belt which increases the strength of the wearer exponentially. This was also placed here by Ardiniss to prevent it from falling into the hands of Chaos. It is guarded by Ice Elementals.