An ancient road as well as the remnants of a dock and structures were found submerged in a lagoon located in Venice, Italy. While there is a lagoon there now, this proves that the location once had some dry land. The discoveries were located in the Treporti channel in the northern part of Venice's outer lagoon.
A research team conducted sonar scans and archaeological dives in the channel and that’s when they discovered several stones that had an ovoid underside and a smooth upper face that were very similar to Roman basoli which were stones that were used to pave the upper surfaces of ancient roads.
Additionally, they found 12 archaeological structures within a distance of 1,140 meters (3,740 feet). They measured as high as 2.7 meters (9 feet) and 52 meters in length (171 feet) and could have possibly been part of a road-bed. Then they located other structures around 9 meters (30 feet) underneath the road that might have been part of a dock.
They even found the remains of what they believe were several settlements that were located along the ancient road such as bricks, roof tiles, and even pottery.
Based on what they found, the researchers think that the road connected the dock and settlements to several additional roads that connected other towns in the southern portion of the now-lagoon to the northern Roman trading center of Altinum. Although there would have been lots of dry land in that area during that time, there would have also been a decent amount of water – the sea coast would have been on the eastern side of the road while an enclosed waterway would have been on the other side.
As for when the road and settlements were constructed as well as how long they were in use for, the researchers aren’t entirely sure but they are hopeful that radiocarbon dating will help to answer those questions. (A reconstructive photo of the road can be seen here.)
In an email to Live Science, Fantina Madricardo, who is a geophysicist at the Institute of Marine Science (ISMAR) in Venice, stated, “The Venice lagoon formed from the main sea-level rise after the last glaciation, so it's a long-term process,” adding, “We know that since Roman times — about 2,000 years — that the sea level there rose [up to] two and a half meters [8 feet].”
The study was published in the journal Scientific Reports where it can be read in full.