Euripus

The western Campus Martius was low, marshy ground, and building on it meant moving water off it first. When Agrippa began his construction campaign there in the 20s BC he cut an artificial channel across the plain and called it a euripus. The Greek word meant a strait with a strong current, and Romans had adopted it for an artificial channel of water: Caesar dug one around the arena of the Circus Maximus to keep the beasts off the crowd, and ornamental versions ran through the gardens of wealthy houses. Agrippa’s ran roughly parallel to the Tiber and emptied into the river somewhere between the modern Ponte Vittorio Emanuele and Ponte Sant’Angelo, carrying the overflow from the Stagnum Agrippae, the ornamental lake beside his baths. The Aqua Virgo, completed in 19 BC, kept it full of clean running water, and Frontinus, a senator who later took charge of Rome’s water supply and wrote a survey of it, notes that the channel took its name from the aqueduct.

Agrippa set out a Greek-style designed landscape in the middle of Rome: a plane grove, an artificial lake, sculpture among the trees, and a canal of clear running water through the whole. Strabo mentions a bronze lion by Lysippos standing in the grove between the lake and the channel.

Seneca describes plunging into the cold water on the first of January as a New Year ritual, which suggests the canal doubled as an open-air cold pool for the baths next door. Ovid, writing from exile on the Black Sea, lists the lake and the Virgo’s water among the sights of Rome he missed. What Agrippa built as drainage had become, within a generation, one of the pleasures of the city.

A stretch of the canal survives beneath the Palazzo della Cancelleria, the Renaissance palace of the papal chancery near Campo de’ Fiori, and part appears on the Severan Marble Plan, the third-century marble map of the city that survives in fragments. The channel had a semicircular cross-section about 1.73 meters across, flanked by two parallel walls built in reticulate work and squared tufa blocks.

Those techniques point to an early Augustan date, and the level at which the remains sit matches that of a Republican tomb found under the same palace. The channel has also been read as Neronian, belonging to a later reorganization of the Campus Martius, while others have kept it in the early empire, close enough to Agrippa’s own time for the canal to be his. A separate argument discounts the remains altogether and places Agrippa’s Euripus in the southwestern Campus Martius, north of the bridge he built across the Tiber, where the Aqua Virgo could have supplied it on its own, with no overflow needed from the lake. It has also been identified as the line of the pomerium, the sacred boundary between the city proper and the ground outside, though nothing from the Augustan period itself supports the claim.

Agrippa’s Euripus did not survive antiquity. The aqueduct that filled it did: the Aqua Virgo still carries water into central Rome, where it surfaces in the Trevi Fountain.

FURTHER READING

1. Anne Hrychuk Kontokosta. “Building the Thermae Agrippae: Private Life, Public Space, and the Politics of Bathing in Early Imperial Rome.” American Journal of Archaeology, vol. 123, no. 1, 2019, pp. 45–77. JSTOR, https://doi.org/10.3764/aja.123.1.0045. Accessed 1 Aug. 2026.
2. Jacobs, II, Paul W., and Diane Atnally Conlin. Campus Martius: The Field of Mars in the Life of Ancient Rome. Cambridge: Cambridge University Press, 2015. Print.
3. Evans, Harry B. Water distribution in ancient Rome: the evidence of Frontinus. University of Michigan Press, 1997.
4. Taylor, Rabun M. Public needs and private pleasures: water distribution, the Tiber river and the urban development of ancient Rome. No. 109. L’Erma di Bretschneider, 2000.
5. Lloyd, Robert B. “The Aqua Virgo, Euripus and Pons Agrippae.” American Journal of Archaeology, vol. 83, no. 2, 1979, pp. 193–204. JSTOR, https://doi.org/10.2307/504901. Accessed 1 Aug. 2026.