Njal Ragmar's Tomb is the second of the Ragmar Tombs.

If you have visited the first Ragmar Tomb your will have found Skelt's body and read his death note.
From that note you will know the location of the second Tomb, for those who have not visited the first tomb, Skelt's note points to the area south of Meeko's Shack.
The tomb has three levels and on the first level there is an large area that is not easy to find.
All levels are fully navmeshed and optimized.
When you first enter the tomb look for Togbar's journal, it will give you an idea of what to expect as you explore the tomb. Once inside the tomb look for the clue to the location of the next tomb.
This is not an easy tomb, especially for low level characters.