This bridge over the Singel is called the "Torensluis" (Towerlock). Build in 1648 it is the oldest bridge in Amsterdam in its original state and with a wide of 42m also the broadest of the city. This because there was a tower build on the bridge on the left side called the Jan Roodenpoort Tower ( part of the middle-aged defense works as gate and demolished in 1829). The dungeons of that tower are still in the fundament of the bridge as you can see and are nowadays used for exhibitions. In the list of amsterdam bridges this one is nr. 9 out of 2361 normally numbered. Here a link to that list. Than you see that a lot of bridges even still have no number or a special code that they doesn't belong to the city of amsterdam but are property of the railroad company or from the ministry of waterworks etc.
One for sunday bridges here.