Venice Is an Upside-Down Forest. Startling Engineering Has Kept City Afloat With Just Wood for More Than 1,600 Years.
Venice, for many, possibly ranks as one of the most beautiful cities in the world. Its archaeological history makes it a treasure for civil engineering enthusiasts. In 2025, the city turned 1604 years old, and so did its roots, which continue to display immense durability despite the passage of so many decades, stated BBC.
Locals have long known that Venice is an upside-down forest. The foundation is made of several short wooden piles, whose tips are facing down underground. The wooden piles belong to trees like larch, oak, alder, pine, spruce, and elm, measuring between 3.5m (11.5ft) to less than 1m (3ft) in height. These piles have been supporting this magnificent city for centuries. Experts continue to be surprised by this astounding achievement, which they can't even consider for stronger materials like steel. "Concrete or steel piles are designed [with a guarantee to last] 50 years today," said Alexander Puzrin, professor of geomechanics and geosystems engineering at the ETH university in Zurich, Switzerland. "Of course, they might last longer, but when we build houses and industrial structures, the standard is 50 years of life."
For a long time, multiple researchers have been interested in understanding how this fascinating system came to be. No one knows for sure how many piles have been used to keep the city afloat. Examinations have revealed 14,000 wooden poles in the foundations of the Rialto Bridge, and 10,000 under the San Marco Basilica. "I was born and raised in Venice," said Caterina Francesca Izzo, environmental chemistry and cultural heritage professor at the University of Venice. "Growing up, like everyone else, I knew that underneath the Venetian buildings, there are the trees of Cadore [the mountain region next to Venice]. But I didn't know how these piles were placed, how they were counted and knocked down, nor the fact that the battipali (literally the 'pile hitters') had a very important profession. They even had their own songs. It is fascinating from a technical and technological point of view."
Researchers believe that Battipalis placed the piles as deep as possible under the city. They started from the outer edge and moved steadily towards the foundations' centre, until the piles couldn't be pounded any further. After this piles were sewn together to formulate a regular surface. Later, transverse wooden structures were placed above the piles. For bell towers, the workers placed a zatteroni (boards) or madieri (beams), which were 50cm thick. For other structures the wooden structures were around 20cm (8in) thick. Above the wooden structures, the building's stone was laid.
Experts claim that the Republic of Venice began monitoring wood production during the construction of the city to provide sufficient wood for several processes. "Venice invented sylviculture," explained Nicola Macchioni, research director at the Institute for Bioeconomy at Italy's National Council for Research. "The first official sylviculture document in Italy is indeed from the Magnificent Community of the Fiemme Valley [to the north-west of Venice], dating from 1111 A.D. It details rules to exploit the woods without depleting them." Sylviculture refers to the practice of cultivating trees. They must have put into action wood conservation processes decades before writing them down, whose results are noted even today in places like the Fiemme Valley.