The fish doorbell in Utrecht is back for another season! “Did you spot a fish? Press the Fish Doorbell! Then our lock keeper can let the fish through.” https://visdeurbel.nl/en/
The Fish Doorbell — The Fish Doorbell
Did you spot a fish? Press the Fish Doorbell! This alerts our lock operator to let the fish through. The Fish Doorbell is in Utrecht, NL.
kottke.org