As you travel through Svartalfheim in God of War Ragnarök, a handful of Odin's Ravens will be available to you without the need to complete additional main story quests or sidequests. Here's what you need to do to claim the Raven in Athjof's Rig.
Athjof's Rig is to the northwest of the Bay of Bounty, which also is near where the Ravens at The Watchtower and Radsvinn's Rig are located. Fortunately, the Raven at Athjof's Rig does not require additional quest progression to reach and, like others, can be returned to later on in the story. There are a total of 48 Ravens scattered across the realms of the game.
Where to Find Odin's Raven in Althjof’s Rig
The Raven at Athjof's Rig can be found immediately upon entering the area. After disembarking your boat, climb the chain that leads into the area. Once you've entered, look to your left, and you will spot a cluster of broken panels on the rig site. The Raven will be hard to miss as it is directly in the middle of an opening of these panels. This Raven is the only one found in the area.
Several of the Ravens, that are easily claimed in Svartalfheim are near each other, so they can luckily all be found as you travel the area without any additional backtracking.