Completed Project

Temple of Hercules

Rome, Italy
Did You Know?
The Temple of Hercules, situated in the Forum Boarium on the eastern bank of the Tiber, is one of the oldest extant buildings in Rome.
A Closer Look

Temple of Hercules


The Temple of Hercules, situated in the Forum Boarium on the eastern bank of the Tiber, is one of the oldest extant buildings in Rome. It is purported to be the work of the Greek architect Hermodoros of Salamina, who engineered a circular layout of 20 Corinthian columns orbiting around a central cylindrical stone block. This structure was created to be the circular temple where Hercules rested after his tenth labor of rescuing the cattle of Geryon from Erytheia. The temple’s famed columns are slender and exhibit no swelling or entasis, instead extending directly upwards giving the structure a lofty appearance. These fluted column shafts are surmounted by beautifully rendered Corinthian capitals. Their highly articulated acanthus leaves, deeply carved stalks or cauliculi, and curling volutes, create a contrast between light and shadow in the carving. The temple eventually took on a Christian identity in 1140, when the Papal Bull of Innocent III decreed that the temple be used as a church dedicated to San Stefano.

How We Helped

The marble components of the Temple of Hercules have endured considerable deterioration over the two millennia the structure has stood in the Forum Boarium. The columns titled at a severe angle, and there was a substantial loss of material around the joints of the marble blocks that compose each column, especially along the marble’s natural veins. This greatly increased the risk of their movement or collapse. The tuff blocks of the podium, upon which the temple’s fragile columns rest, had undergone advanced erosion as well. On the interior, the surfaces of the medieval frescoes had gone untreated for a considerable period of time and had experienced notable deterioration. In 1996, the Temple of Hercules was placed on the World Monuments Watch. Conservation work focused on securing the stability of the fragile structure, conserving the eroding marble surfaces and rare Christian frescoes it housed, and surveying the impact of local geological stability and modern development to detect and preempt future threats to the site. To eliminate the structural risk afflicting the building, stainless steel and titanium elements were employed to anchor the new roof to the column capitals without endangering the original architecture. The tuff podium and pavement, which were exposed by previous excavations, were first conserved to their original heights with new stonework and then partially reburied to safeguard their stability. Within the temple’s interior, all marble and plaster sections of the walls were cleaned, consolidated, and repaired and the fifteenth-century fresco resting above the altar was treated and consolidated.

Why It Matters

With a history of continuous occupation stretching back over 2,000 years, the Temple of Hercules represents a palimpsest of architectural layers and uses. The temple is the only surviving ancient sacred structure in Rome that is made of Greek marble. It is composed of Pentelic marble, a stone originating in the quarries of Mount Pentelikon in the plain of Attica. The building also houses a major work of the Roman fifteenth century, a scarcely documented era in comparison to baroque architectural and decorative programs. The temple remained an important icon of the Roman urban landscape into the eighteenth century and was significant enough for the renowned draftsman Giovanni Battista Piranesi to record in his seminal work Vedute di Roma. Through this WMF conservation initiative, the different phases of the temple's history were preserved.

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