Barrier Tower has many Upgraded Watchbot Skeletons manning Harpoon Turrets Mk2. Inside the tower there are Beds that are not marked as private, meaning they are free to use, the bed in the middle has a table in the way, but you can still sleep in it by clicking on it while standing on the stairs above it. The Watchbot skeletons can often have [Specialist] and [Masterwork] grade Eagle's Crosses.
Interestingly, this outpost has walls blocking an easy passage to use the side of Sonorous Dark to get an easy route to Ashlands.
Do note the gap in the photo is impassible and you would have to swim through the acid water AND past the tower to get across.
Turret guards on the tower. Good luck!