Venice is covered in battlements. They run along the Doge's Palace, the Procuratie Vecchie in Piazza San Marco, the walls of the Dogana da Mar, the roofline of Ca' d'Oro, garden fences and even a nineteenth century factory entrance on the Giudecca. Apart from the Arsenale, none of these are military battlements, and their role is mostly symbolic (Squassina, 2025, p. 750).
That is the useful correction to carry around the city. The merlon outlived the job it was invented for. It became a marker of power and of ground worth protecting, so it was carved onto palaces, warehouses, monastery walls and small private gardens, in a range running from the Middle Ages to the nineteenth century (Squassina, 2025, p. 750).
The other half of the story is less known. The idea that the lagoon alone defended Venice distracts attention from a defensive system the city planned from its establishment and developed over time (Squassina, 2025, p. 748). Venice was fortified. Most of the fortification is gone, some of it survives as traces inside later buildings, and the largest surviving ring of real forts stands on the mainland, where almost no visitor goes.
Why does Venice have battlements?
Because battlements meant something beyond defence. Merlons were architectural devices denoting the medieval places of power, and they were slowly transformed into carved laceworks adorning rich houses, institutional palaces and gardens (Squassina, 2025, p. 750). By the time most of the ones you can see were built, they were a claim about the building rather than a fighting platform.
The clearest evidence is what wore them. The Fondaco dei Tedeschi at Rialto, rebuilt in the fourteenth century, and the salt storehouses at San Biagio were given merlons despite their primarily economic purpose, because they had to be, in the phrase the paper quotes from the scholarship, strong, safe and protected (Squassina, 2025, p. 750). A warehouse full of trade goods needed to look defended whether or not it was.
There is a competing reading worth knowing and worth attributing carefully. The engineer and historian who catalogued Venice in the 1950s put the defensive purpose in question for everything except the Doge's Palace and the Arsenale, and suggested that crenellations on private houses and fondaci were mainly ornamental, deriving from Arabic patterns such as the mosques of Cairo or the courtyards of the Alhambra (Squassina, 2025, p. 750). That is a suggestion carried in the source, not a settled finding.
Was Venice ever a fortified city?
Yes, and the evidence is scattered across the map. The Grand Canal itself is thought to have been closed by a chain during the Hungarian invasions of the ninth and tenth centuries, set close to the church of San Gregorio (Squassina, 2025, p. 748). The main entrance from the sea, between the island of the Certosa and the north eastern watergate of San Nicolò, was guarded by a wooden tower from the early fourteenth century. By the end of that century it had been reinforced into twin towers called the duo castelli, connected by chains (Squassina, 2025, p. 748).
On the landward side the strongholds of Marghera and then Mestre defended the Republic until the sixteenth century (Squassina, 2025, p. 748).
The eastern sestiere carries the memory in its name. Castello is recorded from the ninth century and refers to the Castellum Olivolense, a lost early medieval fortress thought to have stood on the site of the former cathedral of San Pietro and to have been wide enough to reach the present Arsenale. Medieval chronicles say this first fortified core was enlarged by doge Pietro Tribuno, who ruled from 888 to 911, and connected by fortifications to a twin castle on the site of the Doge's Palace (Squassina, 2025, pp. 748 to 749).
The Arsenale: the one wall that was doing military work
The Arsenale is documented in the early thirteenth century as a rectangular fortification defended by walls and connected to the lagoon through a channel crossing an arch, the arco de Arsana (Squassina, 2025, p. 749). It is the exception the rest of this page is measured against.
Two merlon systems meet at the entrance, and they are easy to tell apart once you know to look. Brickwork merlons of the Ghibelline type surround the fortifications, while carved gothic stone merlons crenellated the former front facade, which is now included inside a later building (Squassina, 2025, p. 751). Plain brick for the working wall, carved stone for the face the Republic showed visitors.
The enclosure is large enough to change the character of a whole district. It covers 478,000 square metres, made up of 136,380 square metres of buildings, 224,620 of open space and 117,000 of water, which is roughly 20 per cent of the Castello district (Camerin, 2024, p. 64). Most of it cannot be walked into. The Italian navy still owns 77,000 square metres of the site (Camerin, 2024, p. 68), and the Arsenal remains largely inaccessible to the public (Camerin, 2024, p. 70). The exhibition months are when most visitors get inside, and one of the few interiors they reach is the Gaggiandre, the water canopies built between 1568 and 1573 to shelter rowing galleys (Camerin, 2024, p. 63).
How to date a merlon by its shape and material
The shapes reflect style changes over time. Simple thirteenth century flat and triangular merlons gave way to the three-foiled gothic crenel, which has stone versions, as on the Doge's Palace, and brick ones, as in the articulated crenellations of Ca' Foscari. Renaissance and later merlons are often assembled from geometrical figures such as cubes and spheres: the early sixteenth century facade of the Procuratie Vecchie in Piazza San Marco, the seventeenth century walls of the Dogana da Mar, and a goblet-shaped crenellation on a late garden fence (Squassina, 2025, p. 751). At the end of the sequence, crenellations turned into simple engrailed fence walls surrounding nineteenth century factories and open spaces, such as the Officine Navali at the Giudecca (Squassina, 2025, p. 750).
Material works as a second clue, because the variants mark a hierarchy. Brickwork and simple shapes usually distinguish the military character, probably alluding to strength as the primary feature of a defence, and they also distinguish garden fence walls. Stone is a representative feature, with simple shapes for the fondaci and articulate ornamentation for institutional and private palaces and front entrances (Squassina, 2025, p. 751). Ca' d'Oro is the sample given for refined ornamental stone merlons (Squassina, 2025, p. 750). So brick usually means work or garden, and carved stone usually means status.
What stood where the Giardini Reali are now
Four crenellated granaries. The view of Venice by Jacopo de' Barbari, a portrait of the city in 1500, still recorded public and private buildings provided with battlements and merlons, among them the lost Barozzi House at San Moisè and the Terranova Granaries, four big crenellated stores connected by high arches and overlooking St Mark's Basin. They date to the first half of the fourteenth century and were demolished during the nineteenth century to make space for the Royal Gardens (Squassina, 2025, p. 749). Thousands of people cross that ground every day without a marker to tell them.
Two other images record the crenellated city. The procession scene painted by Gentile Bellini in 1496, now in the Gallerie dell'Accademia, shows several crenellated buildings in the Piazza, including the former Procuratie (Squassina, 2025, p. 749). Earlier still, the oldest map of the city, in the fourteenth century codex Chronologia Magna, shows the fortified layout with crenellated walls of both the Doge's Palace and the Arsenale. The plan was drawn by Paolino Veneto in 1346 and is kept in the Biblioteca Nazionale Marciana as Ms. Lat. Z. 399 (Squassina, 2025, pp. 749 and 753).
Where the medieval traces survive
Two stops reward a careful look, and both need patience. The oldest remains have often been incorporated into more recent buildings, which hinders their legibility, so stratigraphy is the instrument that detects them (Squassina, 2025, p. 752). Expect fragments rather than a wall.
The first is behind the Prigioni Nuove of the Doge's Palace, a short walk from the Bridge of Sighs. A crenellated wall with a long indented brickwork frame once enclosed the open space there. The rear of the eastern side facade of the sixteenth century prison block is now joined to a tall brickwork fence wall that includes the remains of the earlier, lower crenelled wall. The crenellation was mainly demolished, but the ancient wall still provides a round corner at the opposite end, and its presence has to be carefully detected through stratified details and tiny traces (Squassina, 2025, p. 752).
The second is near Ca' Foscari, where a gothic palace incorporates the evidence of a previous byzantine house surrounded by a crenellated wall. It is still recognisable on the stratified northern corner, where some merlons and the remains of a demolished saw-tooth shaped brick frame survive (Squassina, 2025, pp. 752 to 753). These archaic samples matter because they are the physical testimony of a medieval Venice that appears to have gone.
Where Venice's real forts are
On the mainland, and mostly closed. The fortified ring around Venice was built in two campaigns. The first began in 1882 around the logistical nucleus of Fort Marghera, itself begun at the start of the nineteenth century, first by the Austrian empire and then by Napoleon's troops. The plan remained unfinished and produced three fortresses near the main routes into Venice: Fort Brendole in 1883, Fort Tron in 1890 and Fort Carpenedo in 1892. These first generation works have a polygonal plan, stone and brick walls, and a moat that on the entrance side ran as wide as forty metres (Di Resta, 2025, p. 1320).
Rapid changes in artillery made them obsolete almost at once, and a second, outer line was built between 1907 and 1911: Fort Rossarol at Tessera, the only one on two floors, Fort Pepe near Tessera, Fort Mezzacapo at Marocco, Fort Poerio near Mira, the Bazzera powder magazine, Fort Sirtori between Chirignago and Spinea, and Fort Cosenz at Dese. They stand 4 to 5 kilometres apart and were built as compact volumes in unreinforced concrete, with wells for 149 A-calibre cannons in cupolas that turned through 360 degrees (Di Resta, 2025, p. 1321).
All were decommissioned between the early 1980s and the mid 1990s, and are now split between the Municipality of Venice, the Italian Public Property Agency, the Veneto Region, the Municipality of Mira and a private owner (Di Resta, 2025, p. 1322). Opening is occasional and organised locally, so check before travelling.
