Love locks is a very romantic tradition/costom, believed to be originated from Italy some 100 years ago, during the World War I. A 'Love Lock' basically is a padlock fixed to a bridge or fence by sweethearts to show their loyalty to each other. It is there in many cities all over the world with different beliefs and traditions.
In the city of Cologne, couples put padlocks as a proof of their love on the 'Hohenzollern Bridge' over river Rhein and then throw the keys into the river to ensure everlasting love.
While having a closer look to these symbols of love, you will find many colorful customized padlocks with engraves of name, date etc. Also with decorations and personal stuff like rings etc. These locks are present in thousands of numbers and weighs tonnes.