Just as I visited, the city was unveiling several recently completed ships modeled after the ones actually used for trade during Nagasaki's heyday.
This is the famous "megane-bashi", named because the bridge and its reflection in the water resembles a pair of eyeglasses (megane). It's actually only one of many bridges, each linked to a temple up the hill. A helpful sign nearby (shown above) shows a very clear illustration of the connections.