Originally the ground here was sand. Now it's oily slate, compacted through time. Boats often shored here to catch crab and take a break. When pirates found the area, it was worth defending but it proved too difficult to keep. The pirates stole the land from Britain and made a pirate town.
Pirates make difficult neighbors. Every ship passing near the Bay was attacked or almost attacked on their journey. The Pirate City needed to be destroyed by a medium-sized force. But there was only room for a small one. Ultimately a homeless ninja was hired, along with six other ninjas, to take down the city.
"From the rocky beaches of Pirate City we will sneak. We will sneak, we will sneak, until we get to murder head Pirate. His body will float down the crab-shoot of the vast sea."