The publication of Rock of Ages in 1776 gave the world a great hymn, its greatness rests on the purity with which it proclaims the Gospel.
Legend has linked this hymn with a cleft in the rock near Burrington Combe and this location has provided the source for many postcards, the song and its imaginary was once a source for many further postcards and there are even a few postcards linked to Toplady himself.
There seem to be a few people who like mw collect such cards, and my own collection can be seen below: