By far my favourite thing in Cologne (apart from the chocolate museum and the mustard museum (no I'm not kidding)) was the lock bridge.
The lock bridge, which may not really be called the lock bridge if you're a local, is a train bridge over the river that people have attached literally thousands of locks to. The locks say people's names or wedding dates or other memories, and I became slightly obsessed with it... It's like a giant, weird, German, lock-based game of Where's Waldo!
I know there is also a bridge like this in Paris, and there may be more in other places as well! Very enjoyable and sentimental and amazing!
