Capturing an image of this phenomenon on Brooklyn Bridge I did some research and found that the tradition had its roots buried in a romance novel based in Rome. In the story, the two lovers, looking out over the vista from a bridge, took a lock and locked it to the rails of the bridge as a symbol of the strength of their love and commitment to each other, they then threw the key for the lock into the waters below as a testimony to their future. This became a popular icon of romance among, mostly, the Italian youth of NYC.
