As World War I drew closer, the love between two young Serbians, a schoolmistress named Nada and a soldier named Relja blossomed, and they became engaged. Sadly, Relja was sent to war and fell in love with a woman from Greece, never to return to the small Serbian town of Vrnjačka Banja.

Suffering from a deep sadness at the loss of her lover to another woman, Nada wasted away and eventually died, young and alone. Other girls in Vrnjačka Banja saw her fate and began attaching padlocks inscribed with their names and the names of their lovers to a bridge in the town. Hoping it would save them from the fate that befell Nada, thousands of locks were attached to the bridge, and it now stands as a memorial to everlasting love and a tragedy of the heart in World War I era Serbia.