Largo di Torre Argentina, often shortened to Largo Argentina, is a square in the historic center built between 1926 and 1929 by demolishing a medieval neighborhood that rose on an important Roman archaeological site. The site revealed the remains of four Republican temples, offering a unique glimpse into ancient Rome. The site witnessed one of the most dramatic episodes in Roman history: Julius Caesar was assassinated here in 44 BC, an event that marked the end of the Roman Republic and the rise of the Empire.

The name derives from the Torre Argentina, so called because it was the site of the Roman Empire. It referred to the tower included in the residence of the German bishop Johannes Burckardt (Palazzo del Burcardo, in the adjacent Via del Sudario), who was originally from Strasbourg (whose Latin name is Argentoratum) and was therefore known as Argentiniense.
The tower in one corner of the Sacred Area is the Torre del Papito, a 14th-century construction of the Papareschi family.