The Basilica of San Clemente is important for both archaeological and historical research. The church that now stands was built upon a 4th century church, which contains several restored frescoes, and a large amount of recovered roman tiles with Latin inscriptions which were used to reconstruct the walls. This church was also built on the site of an early Roman area, with sites like a Temple of Mithras, a cult imported into the Roman Empire from Persia, which competed with Christianity as the premise of the cult was very similar. There are also roman villas and a street which have been excavated at the same level as the temple. There are also several artefacts, such as busts and large storage jars which have been preserved, which was useful when looking to identify the historical period the temple was built in. There is a spring which runs alongside the temple and villas, which suggests why the homes and temple were built there, as they would have constant access to freshwater. When undergoing the archaeological excavations the water level was extremely high and had to be drained before any more excavations could be completed. This was not the only archaeological difficulty in this project, and when the church underneath the current Basilica was first discovered the entire chamber was filled with rubble, which had to be taken out through a small hole in the ceiling. After this, several of the frescoes were revealed, including one of the Virgin Mary that, despite efforts to maintain it, crumbled to reveal and older fresco in a niche, also of the Virgin Mary but in the Byzantine style. This fresco was interesting when compared to later styles, as the Virgin Mary is depicted like a Byzantine princess with a headdress and not a halo. The current Basilica also has some fascinating artefacts, such as a genuine Cosmati pavement. These pavements were designed by a thirteenth century family, and uses geometric swirls that can be followed infinitely. These pavements are almost solely used for religious buildings, as the infinite circles are symbolic of the never-ending life for the followers of Christianity, and the infinity of the universe and God’s ultimate power. These pavements can also be found in places like the Sancta Sanctorum, the pope’s private chapel. Due to the exquisite craftsmanship of these pavements, they were expensive, therefore suggesting that at the time the current basilica was built, and Christianity was thriving in Rome as the Church was wealthy enough to commission this pavement. The current basilica is run by the Irish Dominicans, and has been since 1667 when Pope Urban VIII gave the catholic clergy refuge when they were expelled from England. The current basilica has several frescoes dedicated to Saint Catherine, such as one of her attempting to preach Christianity to several Roman officials, and images of her martyrdom on the wheel. There is also an apse mosaic showing the tree of life, in a Byzantine style, with images of prophets and the disciples depicted as sheep below this. This is a very ornate apse mosaic, and is one of the earliest made.