A view of the San Marco Basin in 1697.
The architectural wonder that is the city of Venice, with millions of visitors each year, is the product of centuries of work and thoughtful approaches to specific challenges. It wasn’t just built all of a sudden out of nowhere; instead, Venice owes its development to centuries of adaptations and innovations to the harsh water conditions. The city is in the midst of a lagoon, a more or less shallow body of water that sits between the mainland and the open sea, and its foundation rests on a number of small islands and mudflats. To build a city in this area meant confronting problems related to water, soil, and perennial flooding; thus, anyone who chose to settle in Venice simply had to find ways to build a stable and enduring settlement.
The construction of Venice began around the 5th century, when groups fled to the lagoon in search of refuge from invasions on the mainland. It was known locally to fishermen and salt workers, but it would never have been a likely choice for building a city under normal conditions. The lagoon was safe from attack because enemies always found it difficult to navigate through the shallow waters and shifting sandbanks. However, the ground was soft, wet, and unsuitable for building, since it was composed mainly of layers of mud, silt, and clay. In addition, nobody would have built on the soil itself because any structure built on it would probably sink or move. People had to find a way to build a firm base for their houses and buildings, and they got to work with available materials and techniques.
Wooden materials were the core of Venice's formation, and the type of wood determined the long-term stability of the city. The builders relied on alder and larch, which are trees that grow in swampy areas and have evolved to naturally be water-resistant. The tees were cut down, stripped of their branches, and driven into the ground as piles, which are long wooden stakes/poles that worked as the city’s hidden support system. Workers would pound these poles deep down into the mud (often several meters into the ground) until they hit a harder layer of clay or sand that was firm enough to keep the poles straight and firm. The poles weren’t just randomly placed but were arranged in tight clusters, with each cluster supporting a specific building or section of the city.
On top of these wooden piles, layers of stone or brick were laid by the builders, which together formed strong foundations upon which construction could be carried on. The stone was often shipped from quarries on the mainland across the lagoon by boat, a process requiring careful planning and coordination. Flat stones made up a solid base on which bricks could be laid in a way that evenly distributed all of the weight. This technique enabled the structures above to remain free from cracking or shifting as the ground beneath settled. The layers of stone and brick also shielded the wooden piles from air exposure, which could lead to rotting. The builders, by constantly submerging the wood deep in the water, away from any air, ensured centuries of durability.
Lightweight materials were used in the buildings themselves to lessen the load on the foundation. Usually, builders did not use heavy stone. Rather, they would use brick for the walls and wood for the floors and roofs. Bricks were a practical choice because they were easier to transport and manipulate than stones. They could easily be made locally from clay dug up from the lagoon. Many of the walls were also constructed so that they were leaning slightly towards the center of the building, allowing for weight to be distributed equally and preventing possible collapses. The sloped roofs allowed for rain to run off easily, thereby avoiding leaks and reducing water damage. Such use of lightweight materials and careful design allowed the wooden piles and soft soil to support large structures like churches.
The process of building Venice didn't just stop with the first series of constructions but rather continued over centuries, as the city evolved and changed. With time, new structures were erected, while existing buildings were improved upon, repaired, or replaced. The canal and bridge networks in the city were expanded as well. The city layout developed organically, as winding paths and narrow streets tied everything together. The bridges were often made of wood in the early years, but the wood was later replaced with stone. The builders also developed systems to collect and store rainwater, as there were no natural sources of fresh water in the lagoon. Large cisterns were installed in public squares, lined with clay to make them waterproof, and rainwater was funneled into them through pipes and gutters.
The construction of Venice relied a lot on a labor and organizational system that worked to its advantage despite its challenging location. Craftsmen, such as carpenters, stonemasons, and bricklayers, were taken in from the mainland and other parts of Europe on the promise of security and work. There were also boards tasked with the oversight of different public works wherein item allocation was efficient and standards of work were maintained. In the end, the mixture of individual capability, collective service, thoughtful planning, and good construction materials made it possible for a city to be constructed and maintained for centuries even in the worst of conditions.