Amsterdam has more than 1500 bridges and many of them are drawbridges to let the big ships with transports over water get through. When you hear a bell ringing and the red lights start to blink, you know the barriers will come down very soon and the traffic has to stop immediately.
It is always funny to see a part of the street coming up and watch the other side of the bridge. When you have a good look you can see some texts of poems painted on the bridge, to entertain the waiting people.
See for other Sunday Bridges here.