Forum Boarium means cattle market and this was the function of this market square in ancient Rome. On the forum several temples were built, like this one for Hercules Invictus, that dates from the 2nd century BC. Sometimes the temple is wrongly named the Temple of Vesta, because of the similarity of the round shape with the Vesta temple on the Forum Romanum. In 1809-1810 the temple, that was used a a church since the middle ages, was restored by architect Valadier in its original state, and so it is depicted in this micro mosaic. The ´Fontana dei Tritoni´ in front of the temple was erected in 1715 by architect Carlo Francesco Bizzaccheri on commission of Pope Clemens XI. This fountain consists of a basin in the shape of a star with eight points (part of the coat of arms of Clemens) and a rock above it with two tritons, carrying a shell.
Micromosaics werre collected by travelers during their Grand Tour: especially larger ones like this one were very popular.