K?ln, Germany

K?ln is the fourth largest city in Germany, and is also one of the most developed cities in the country. It boasts numerous well-known attractions such as K?lner Dom. It also features a landmark of love: colorful concentric locks on the fence of Hohenzollern Bridge. The locks weigh 2 tons and add to the weight of the bridge, so the administration company warned to discharge them. However, due to strong opposition from the public, the locks have been preserved.