Throughout the zone there are many breakable walls. Some separate you from where you need to go, opening additional sections of the zone. Others are walled-up alcoves containing a dusty coffin, a dusty vase, or sometimes both. Destroying them may reveal nothing, a monster, or just some coin. Dusty vases can also appear in other places in plain sight.
There are 4 classes of vampire underlings in the Tombs: Neonates, Adherents, Bloodsworn, and Elders. The Elders are only seen in The Crypt of T'haen.