Petrovaradin Fortress

Start with the stone under your feet. It is worn smooth in places, rough in others, and it carries the warmth of the afternoon long after the sun has moved on. Below you, the Danube runs wide and brown-green, and on the far bank the rooftops of Novi Sad spread out toward the plain. The wind up here has room to move. You can hear it in the trees along the walls, and sometimes you can hear the river traffic too.

You are standing on Petrovaradin Fortress, on the right bank of the Danube, in Serbia's northern province of Vojvodina. The fortress sits on a rocky outcrop. That small detail explains almost everything about this place. The land around Novi Sad is famously flat, part of the great Pannonian Plain. So a hard ridge of rock beside a major river was something armies noticed, and wanted, for a very long time.

People settled on this rock long before any of the walls you see today. Archaeologists have found traces of prehistoric life here, and the Romans later used the site as part of their frontier along the Danube. For Rome, this river was a border. Across the water lay lands outside the empire. In the Middle Ages, a Cistercian monastery stood on the hill. The Cistercians were a strict Catholic monastic order, known for building on remote, defensible ground.

Then came the long struggle between two great powers. In the sixteenth century, the Ottoman Empire pushed north into Central Europe, and this crossing point fell under Ottoman control. It stayed that way for well over a century. When the Habsburgs, the Austrian dynasty that ruled a vast empire from Vienna, drove the Ottomans back in the late seventeenth century, they decided to turn this rock into something permanent.

Construction of the fortress you see began in 1692. It did not finish quickly. Work went on for the better part of a century, and the fortress was considered complete around 1780. That is roughly three generations of soldiers, engineers, and labourers. Many of the people who started the work never saw it finished. The design followed the star-shaped style of the era, with angled bastions so that defenders could cover every approach with crossfire.

The fortress was tested before it was even complete. In 1716, a large Ottoman army besieged Petrovaradin. The Habsburg forces were led by Prince Eugene of Savoy, one of the most celebrated generals of his age. His army won a decisive victory here. The battle helped to end Ottoman ambitions in this part of the Danube, and it shifted the balance of power in the region for good.

Because of its strength and its position on the river, the fortress earned a nickname you will hear often: the Gibraltar on the Danube. Gibraltar is the famous rock fortress at the mouth of the Mediterranean, long seen as almost impossible to capture. The comparison is generous, but it gives you a sense of how seriously this place was taken. Here is one surprise — after 1716, the fortress was never really put to the full test of a great siege again.

Now, look for the clock tower. It is one of the most photographed points on the walls, and it holds a small trick. On this clock, the hands are reversed. The large hand shows the hour, and the small hand shows the minutes. The usual explanation is a practical one. Boatmen and fishermen on the Danube needed to read the hour from far away, so the hour hand was made the bigger of the two. Locals often call it the drunken clock.

Here is the second surprise, and it lies beneath you. The fortress is not only walls and towers. Under the rock runs a network of military tunnels, built on several levels, stretching for many kilometres. Soldiers could move unseen between positions, and the passages could also be used to place explosives under an attacker. Parts of these underground galleries can be visited with a guide. Inside, the air is cool and still, even on a hot summer day.

The fortress also has a darker side. For a long period, parts of it served as a military prison. One prisoner became very famous later. Before the First World War ended, a young soldier named Josip Broz was held here. Decades later, the world would know him as Tito, the leader of socialist Yugoslavia. It is a strange thought — the future head of a country, locked inside a fortress built to defend an empire that no longer exists.

Today the mood is very different. The old barracks and buildings of the upper fortress now hold artists' studios, galleries, cafés, and the City Museum of Novi Sad. Painters and sculptors work in rooms where soldiers once slept. Every summer, the fortress also hosts EXIT, one of the largest music festivals in Europe. For a few days, the bastions fill with stages, lights, and many thousands of people. The walls that once kept armies out now keep the music in.

Take a moment to walk the edge of the upper terrace. From here, you can follow the line of the river and the bridges that cross to Novi Sad. Below the walls lies the lower town of Petrovaradin, with its narrow streets, small churches, and low houses. It feels like a separate, quieter world from the city across the water. Look down at the brick and stone, and you can see the patches of repair from different centuries.

Before you leave, stand still for a few breaths. Listen to the wind, the voices of other visitors, perhaps the faint sound of the river. Look once more at the clock tower and its reversed hands. As you walk down the slopes toward the town, notice how the walls rise behind you and slowly close off the view. The rock is still here, still watching the Danube, just as it has for thousands of years.