I tried one at lv30 with a full alliance. We got owned, badly. When your group is ready to go, everyone goes to the Gate Guard and gets a free tele to the outpost of the region you choose. You run around the map looking for the Beastman Banner. Assemble your team, buff up, and prepare for a garrison-style battle involving several waves of mobs, each one progressively harder (I *think* there are waves, in all honesty we didn't even get to kill a single dude in the first wave before alliance wiped).
If anything, it's a great way to get a free tele back to the town you're starting this in. They give you a Gate Glyph (rare/exc) before you warp to the outpost, which works very similar to Instant Warp but instead returns you to your home nation instead of your home point.