"place them where you want", they said. But if you want a consistent world, not every placement will make equal sense. Find thoughts and inspiration on where (and why) to put the Raven's purge sites.
Beware:
Spoilers ahead
Although your GM might have an entirely different view on the world. You have been warned, though.
Stonegarden
Not much to say here - it's a dwarven fortress in the mountains. Rumor has it that they secretly ally with the Urhur Orcs, so placing it near makes a lot of sense.I suggest the mountains to the northwest of Ravenland, E8 for example