The Roman Empire theme is exquisitely subtle on this one. Welcome to the last installment of Let's Discuss Landmarks! And what a ride it has been. The participation has been up and down, mostly down, and my own pace was a bit slowed at times, but now the series stands entered into the forums, for future generations to ponder upon the folly of some and to marvel at the prescience of others; like a beautiful monument that shall endure the ages, like a landmark.
Anyway uh. Let's discuss Wolf Den. This one can really make your life hard. What to do about those cards that you really only want one of? Trashers like Chapel are one of the first things that come to mind - it will always give you -3 VP, unless you can trash it with yet another card. Potion has similar issues. But often, these -3 VP are not what makes you go for another strategy. It should be noted that Ruins can get extremely swingy with this; if you split 5-5, it may be that you end up with 0 VP and your opponent with -15.
The endgame becomes more interesting (as with many Landmarks); if you manage an early 3-pile, then you can be pretty sure that your opponent will still have some uniques in their deck. It also challenges common wisdom about Duchy dancing, because that first Duchy will not yet give you any points.