Another kind of lock

 It has apparently become the custom many places in Europe for couples to create "love locks".  A couple engraves a padlock, locks it to a bridge, and tosses the key into the river.  We saw them on many bridges, although in some places they have been banned because the added weight on the bridge was an issue. These were on a railing along the Main in Wurzburg.

There is a long row of locks: