The Rainbow Bridge is the theme of a work of poetic prose written some time between 1980 and 1992, whose original creator is unknown. The theme is of a mythological place to which a pet goes upon its death, eventually to be reunited with its owner. It has gained wide popularity amongst animal lovers who have lost a pet. Although no major religion specifically refers to such a place for pets, the belief shows similarities with the Bifröst bridge of Norse Mythology.