Free: All time
The story goes that it all started when a newlywed couple revived the tradition of sealing their vows by placing a padlock on the rail of the Luzhkov Bridge. The key was thrown into Moscow River. Within a few weeks, the bridge railings were covered in padlocks. While the city wanted to rid the padlock, they realized the popularity of this custom. So after cutting off the original padlocks off the railings, the city erected a symbolic tree made of steel in the center of the bridge and encourage Muscovites to use it as a replacement. The tree filled up quickly. Today, there is a whole population of these metallic trees along the bridge and the embankment.
Address: Luzhkov Bridge, Moscow
Direction: Metro Line 2, 6, or 8 to Tretyakovskaya Station
Photo credit: Tatters (Flickr CC), Kaplar (Flickr CC), Kishjar (Flickr CC)