Hope County Jail (Story Mission)
The central hub of Faith's territory, and one of the locations that's already on your map when the game begins. When you arrive, it's under siege by hostile forces.
As with many sieges, the enemy is completely distracted, making them sitting ducks as far as you're concerned. This is a good place to practice your chain takedowns, if you've unlocked that perk.
Clear the enemies to automatically begin a cutscene where you reunite with Whitehorse.
Another siege will break out during this. Mount the wall and shoot them down (or fight them on the ground, it you'd rather). While some of this wave may arrive in vehicles, they'll all attack on foot, and there are no heavies.
Kill the first wave, and you'll hear about trouble on the west wall. Run over there to deal with a new wave, this one with a mounted turret gun.
The siege is now going to be about defending these points until the cultists break through, or make their last stand. The quickest thing to do is actually let them break the gate. This short-circuits you right to the end of the scenario, where Angels attack, spurred on by three speaker trucks. Destroy the trucks with grenades (or the explosive of your choice).
Dispose of any lingering enemies to complete the mission.
Then go through the cutscene of introductions and plot hooks to complete the mission again.