Inspired by those bridges over the Seine where lovers attach padlocks to the bridge to proclaim their affections.
The padlock model is really simple, and took all of 15 minutes. All the padlocks use the same basic material graph, but each one varies the (many) parameters a bit. I tried doing it randomly, but it was better when hand tweaked.
I wasted 2+ hours trying to use the rigid body physics to position the padlocks, but the system is well-flaky at the best of times, and this task was not a small ask. Gave up and just positioned them manually.
It's a labour of love :-)