Here is the Temple of Hercules Victor. When built, this would have been on the banks of the Tiber, or at least had a clear view of the river. The level of the city has risen some 17 feet since Roman days, so this now sits downhill from the Lungotevere (the street that runs along the riverbank). The tile roof is a much later reconstruction. This temple is the oldest surviving marble building in Rome, dating to approximately the 2nd century BC.
In the plaza in front of it there sits the Fountain of the Tritons, completed in 1715 as part of a renovation project for the plaza in front of Santa Maria in Cosmedin, the medieval basilica that houses the famous “Bocca della Verita” and the skull of St. Valentine.
The Temple of Hercules Victor and the neighboring Temple of Portunus (not visible in this view) were converted into Christian churches in the early post-Pagan era, thus their relative high degree of preservation. Neither are active churches now. While the Temple of Hercules Victor today is solid and stable, work is ongoing on the Temple of Portunus and both remain closed to visitors. The closures may also represent a side effect of the budget woes currently besetting Italy.