South of the chapel, past the Stonecrown mine, the ground splits open: Stonecrown Gorge runs half a kilometre from the hills down to the bay, its walls sheer rock, a river in the bottom of it. Under the hills it is forty metres deep and sixty across, and there is one way over: the Chain Bridge, a plank deck slung from two great iron chains between timber towers, thirty-odd metres above the water. It is lit by lanterns at either end after dark. Look for the little bridge on the map.
Nobody can climb its walls. If you fall in, aim for the river: water that deep breaks a fall. Then swim down to the bay, or upstream to where the river begins and walk up the dry floor of the gorge's head and out.