In England during the late 18th and early 19th centuries, oysters were not considered the rare delicacy they are today, and the large number of oysters eaten at that time meant there were lots of shells around. On St. James‘s Day, which was observed on August 5 before the Gregorian, or New Style, Calendar came into use and on July 25 thereafter, children used the shells to construct small decorative grottoes. Sometimes the children begged for pennies as a reward for their efforts. Most of this grotto-building took place in London, and the custom continued up to the 1950s. Discuss
Source: The Free Dictionary