Prince of Wales Fort is a massive star-shaped stone fortress built by the Hudson's Bay Company between 1731 and 1771 on Eskimo Point, at the mouth of the Churchill River where it enters Hudson Bay. The walls are 6 metres thick and 6 metres tall, enclosing a courtyard the size of a small town. The fort was intended to protect the lucrative fur trade from rival powers — it took forty years to build and was surrendered to France without a fight in its first serious test.
The fort is now a National Historic Site of Canada. Access is by boat from the Churchill waterfront, a ten-minute crossing in summer; Parks Canada offers guided tours of the site. No roofs remain, but the walls, gun embrasures, and interior layout are largely intact. The views back to Churchill and along the Bay are excellent.