On the island of Bequia, the best-defended T-shirt shop on Earth:

The French arrived in the 1700s, developing a working relationship with the indigenous people — the Caribs made the actual T-shirts, and the French provided a garrison of troops to repel British attacks. The French defensive battlements became known as Fort Tricot, named for St. Tricot, the Patron Saint of foundation garments.
However, in 1783, in conceding defeat to France and the new United States after the American Revolution, the British ultimately reclaimed Fort Tricot for good, thanks to a small tag attached to the Treaty of Paris with a safety pin.
All that remain of this rich history are the crumbling original T-shirts manufactured by the French. And the guns.
If invaders ever try to seize Fort Tricot, they will be fired upon. And then they will be given a mildly dirty look if they leave and walk back down the hill without buying anything.