As the Piazza Pia in Rome undergoes a major pedestrianization project ahead of the Jubilee Year at the Vatican in 2025, Italian archaeologists have unearthed the remains of a portico and garden attributed to the infamous Emperor Caligula.

Among the architectural remains are a travertine wall, a colonnaded portico, and an open area presumed to have been used as a garden due to the lead-based irrigation pipes found in the space. Facing the Tiber River, Piazza Pia falls within the buried Gardens of Agrippina, a luxurious estate once encompassing a majority of the Vatican.

Inscriptions on the water pipes routed throughout the garden refer to Caligula’s given name, Gaius Caesar Augustus Germanicus, and to that of his paternal great-grandmother. (Caligula earned his nickname, meaning ‘little boots’ in Latin, when he accompanied his father on military campaigns as a child.) The inscriptions indicate how the property was likely handed down from Germanicus’s family line and given to Agrippina the Elder after his death, and subsequently inherited by Caligula in 33 CE after she passed as well, prior to the start of his brief reign in 37 CE. Prior to his assassination in 41 CE, Caligula’s reign had become increasingly tyrannical, and some scholars have suggested that he was suffering from a mental illness.

A statement from the Italian Ministry of Culture suggests that the recently discovered property was referenced in a passage of Philo of Alexandria’s treatise “On the Embassy to Gaius.” Philo’s text described how Caligula had received a delegation of Alexandrian Jews, vying for their rights by drawing attention to their oppression and suffering at the hands of Alexandrian Greeks, in a large garden separating the Tiber River from a monumental portico. Caligula was less than sympathetic to the Jewish strife at the time and rejected the delegation’s requests.

In addition to the ruins, archaeologists led by Daniela Porro, Dora Cirone, and Alessio De Cristofaro also uncovered a slew of terracotta Campana relief slabs embossed with mythological scenes, likely used to shingle roofs and eventually reused as sewage covers down the line.

The discovery comes amid the ongoing restoration and relocation of a second-century Roman fullonica, or textile processing workshop and laundromat, discovered beneath Piazza Pia last month. Construction workers developing an underpass beneath the area were astounded upon encountering the open-air facility rife with mosaics, tanks, and buried vessels to soak garments in. The fullonica is slated to be reassembled and preserved for the Castel Sant’Angelo area to underscore its history and connection to the location.