Engineers working on Florence's famous medieval cathedral were surprised to find hundreds of animal footprints on the centuries-old roof tiles.
The team were carrying out maintenance work on the hundreds of thousands of terracotta tiles covering the roofs and various domes of the medieval cathedral of Santa Maria del Fiore.
Experts are now busy mapping them one by one and cataloguing them in a painstaking process.
Samuele Caciagli is the architect in charge of technical aspects of maintenance at the cathedral.
"We found hundreds of prints of both wild and domestic animals, more specifically, dogs and cats, small birds, some foxes or martens," he explained.
Rather than intrepid animals scaling the building to walk on the roof, it seems the creatures walked across the terracottas when they were originally made.
Carlo Sacconi from the technical team said the tiles, which were all made in the early 1400s in Impruneta, a small Italian town south of Florence famous for its terracotta tile factories, were put out to dry in the open air before being baked in furnaces.
As the soft clay was drying, wild and domestic animals walked over the tiles and left their prints.
Anyone who wants to see examples of the tiles and the prints does not have to climb on to the building's roof, they can simply visit the cathedral museum instead.
"There are eight moulds for the tiles, in two different shapes, one is the classic rectangular shape dating back to the ancient Roman times of Vitruvius," explained the woman in charge of the collection at the museum, Rita Filardi.