Rome makes you see in new ways. Everywhere the old and the older are used to build the relatively new. The street plan reflects classical land use: the mediaeval warren around Campo di' Fiori was built on the parade grounds of the legions, outside the city walls. Or successive generations lay claim to the inherited mantle, as Mussolini did by driving his Via dei Fori Imperiali through the Forums.
The Forums are still amazing despite the depredations of river silt, Vandal invasions, earth tremors and constant looting for materials. For a start, they cover a huge area. And whilst much that remains is in ruins, the scale of the buildings, the width and paving of the streets, cannot but impress you by the complexity of governance, religion and debate that required these developments.
This building is not by any means the grandest or most significant in the Forums. It is interesting because it combines different eras, and tells a tiny piece of the complicated history of the area. For a start, the street level of the Forum was several metres lower than today. Over centuries the silt deposited by the Tiber's regular floods built up the 'floor' of Rome. Taken from the street as it was in classical Rome, you can see in this picture the enormous height of the columns of the temple of Antonius and Faustina. These deities were the parents of the emperor Marcus Aurelius, and Antonius himself began the building in 141AD, for his wife. The roof architrave is still there, with inscriptions of candelabra, griffins and acanthus.
The temple is so well preserved (the best in the Forum) because somewhere between the seventh and eleventh centuries it became the church of San Lorenzo in Miranda. in 1429/30, Pope Martin V gave the church to the Collegio degli Speziali (College of Chemists and Herbalists), at the time officially known as the Universitas Aromatorium. (They still use their adjoining guildhall, which contains a small museum that holds a medicine-receipt signed by Raphael).
The brick steps are modern - and the façade of the church is from 1602.