A padlock is a mundane object, designed to fulfil a specific - and secular - purpose. A contemporary custom has given padlocks new significance. This custom is 'love-locking', where padlocks are engraved with names and attached to bridges in declaration of romantic commitment. This custom became popular in the 2000s, and its dissemination was rapid, geographically unbound, and highly divisive, with love-locks emerging in locations as diverse as Paris and Taiwan; New York and Seoul; Melbourne and Moscow. This book explores the worldwide popularity of the love-lock as a ritual token of love and commitment by considering its history, symbolism, and heritage.