Hunted Demons Forge

During chapter 6.2 you will encounter a cut-scene when you need to talk to a guy in a tunnel. He will tell you several things, then you will be able to proceed out of the tunnel where you will see several blind dragons flying above. Quickly make your way to the first tower. Once you reach this tower, stay next to it until one of the dragons passes by and destroys the tower.

If it hits it directly the tower will be destroyed and this will unlock.

Credit to http://leadexample.net/guides/retail-guides/hunted-the-demon...