Trade Post Supplies are obtainable by raiding monasteries in Ireland. You need the help of your crew to force open doors and lift the ornate lids off of chests, so to grab the Trade Post Supplies, you’ll need to raid the area.
Kells Abbey Trade Post Supplies
Kells Abbey is a raiding point found in the northern region of Meath. You’ll be able to acquire 4 lots of Trade Post Supplies for a total of +280 Trade Post Supplies. You can use these to build Trade Posts.
South Meath Bandit Camp
In a small bandit camp on the river in the southern region of Meath, you’ll find a singular chest that’ll offer up +70 Trade Post Supplies. Even though its a small camp, you’ll need to raid it with your crew in order to open up the chest!