"with the gargoyles carved on its surfaces "

GNU Free Documentation LicenseGargoyle - Credit: Taxiarchos228
A gargoyle is a distinctive carved stone figure placed on the side of buildings.  They have a spout, usually via the mouth, to allow rainwater to drain away from the roof.  This explains the similarity to the word ‘gargle’; the French word for throat is ‘gargouille’.  Gargoyles without this function are technically just called grotesques or chimera, but in practice the original word is used to describe all of these strange creatures. They began to be used in medieval times (in their most recognisable form), often on churches.  Despite their alarming appearance, gargoyles have often been used to protect the building they reside on, by frightening away evil.