TW:WH2 question: How do I find and destroy a herdstone ?

I am trying to colonize Vaul's Anvil with my Dark Elves but the colonize option can't be selected. So I googled and learned that there is a beastman herdstone that I need to destroy. But where is it ? There is a kind of totem there but clicking on it doesn't give me the option to destroy it, so I don't think that's the herdstone. I also killed a Beastman stack that popped up nearby, no luck either.

How do I destroy - or even find - that blasted herdstone ?