Area Sacra temple remains in Largo di Torre Argentina.

Geoff Stringer

This sunken area in the Largo di Torre Argentina, reckoned to be the site of Julius Caesar's murder, contains the remains of four Republican-era temples, all built between the 2nd and 4th centuries BC. These ruins, which are among the oldest in the city, are off-limits to humans but home to a thriving population of around 300 stray cats and a volunteer-run cat sanctuary.