Venice "Ancestor" City Mapped for First Time

John Roach
for National Geographic News
July 30, 2009
The outline of an ancient Roman city buried beneath cropland near Venice, Italy, has been mapped in detail for the first time with the aid of aerial photography, a new study says. (See the Altinum map and aerial pictures.)

Until now the ancient city of Altinum, which dates back at least to the first century B.C., was known only from historical records and a few minor excavations.

The new map of the town's foundations reveals that it was a classic Roman city replete with city walls and gates, a network of streets and canals, homes, monuments such as an amphitheater and a basilica, and a harbor.

In its heyday, the city was fronted by what is now known as the Laguna Veneta, and a "brackish smell" likely filled the air, noted study co-author Paolo Mozzi, a geomorphologist at the University of Padua in Italy.

"You can expect a lot of coming and going, a lot of ships arriving through the lagoon from points in the Adriatic, [and] there were merchants running along the Via Annia," a road that crossed the city, Mozzi said.

Summer was hot and muggy, while winter days were often shrouded in fog.

The findings paint a picture of a sophisticated community with the know-how to thrive in a lagoon environment centuries before Venice and its famous canals emerged, the study authors conclude.

Crop Survey

Today the remains of Altinum lie under fields of maize and soy on the Italian mainland.

For their map, described this week in the journal Science, Mozzi and colleagues took advantage of drought conditions in 2007 to take photographs of the fields in visible and near-infrared light.

Plants growing on top of stone structures such as walls and building foundations suffer greater water stress than plants over canals filled in with sediment, Mozzi explained.

"If you look at it from the air, you see the geometry of these plants, which show underground the geometry of the structure."

(Related: "Huge Pre-Stonehenge Complex Found via 'Crop Circles.'")

Island Living

Modern-day Venice sits on islands in the Laguna Veneta, which is separated by barrier islands from the Adriatic Sea. (See a Venice map.)

Although it's miles away from Altinum, the study authors consider the mainland city to have been an ancestor of Venice.

Scholars believe that Altinum's residents fled their home during barbarian invasions in the fifth to seventh centuries A.D. and colonized the northern lagoon islands.

Records show, for example, that Altinum's bishop left for the island of Torcello in A.D. 639.

A few centuries later, Venice emerged from the dispersed islands in the central lagoon.

"Our point on the connection between Altinum and Venice is the movement of these people from the mainland out to living in the islands," Mozzi said.

"How can they do that? Because they were already very adapted to the lagoon," which became a safe refuge from less water-savvy attackers.

Venice Ancestor

Experts not affiliated with the research agreed that the new map of Altinum is a tremendous advance for understanding the little-known city.

For instance, the survey offers firm evidence that Altinum was a classic Roman port similar to the nearby ancient cities of Ravenna and Aquileia.

However, several experts emphasized that the city's link to Venice is complex.

Rupert Housley, a geographer at Royal Holloway, University of London, is studying how Venice took root at the heart of a lagoon.

The aerial photography alone can't back up the notion that Altinum was particularly well adapted to lagoon living, Housley said.

"Certainly the residents of Altinum may well have contributed to peopling of the islands, probably along with the other coastal towns," he commented via email.

But from the map there appears to be nothing especially unique about Altinum compared with other nearby Roman ports, he noted.

Albert Ammerman, an archaeologist at Colgate University in Hamilton, New York, said Venice arose organically from migrating residents of several coastal cities, including Altinum.

All of those cities' people, he said, "knew how to live in this aquatic environment. They had all the skills and local knowledge, so it wasn't very difficult for them to go out there" and survive.

© 1996-2008 National Geographic Society. All rights reserved.