The Rotunda of St Martin at Vyšehrad: Prague's oldest building with a cannonball in the wall

On the hill of Vyšehrad, south of the centre of Prague, almost everyone heads straight for the neo-Gothic basilica of Saints Peter and Paul and the Slavín cemetery, where Dvořák, Smetana and Mucha rest. A few metres beyond, along the street V Pevnosti, there is instead a small stone cylinder plastered in a pale colour that most visitors pass without stopping: the Rotunda of St Martin. It is the oldest building still standing in Prague and the only monument of Vyšehrad preserved in its original form.

The Romanesque rotunda

It was built in the last third of the 11th century, under Prince (later King) Vratislav II, when Vyšehrad was the sovereign's residence. It is a Romanesque rotunda of minimal dimensions and a geometry readable at a glance: an internal diameter of about 6.5 metres, an apse a little over two metres deep, walls nearly a metre thick. Above the conical roof rises a small lantern topped by a gilded cross with crescent and sun. That is all: a round hall for a handful of the faithful, surviving nearly a thousand years of wars and rebuildings of the neighbourhood around it.

The cannonball

The detail that makes the detour worthwhile is embedded in the wall, to the right of the window above the entrance: a cannonball. It is a memento of the Prussian siege of Prague in 1757, during the Seven Years' War, and it was left there deliberately, walled into the plaster, like an exposed scar. It can be seen with the naked eye from the street, without needing to go inside.

The restoration

The rotunda has come down to us almost by chance. Once the hill was turned into a fortress, the building ended up used as a gunpowder store, including during the Thirty Years' War. In 1841 a road project between Nové Město and Pankrác threatened to demolish it: it was saved by Count Karel Chotek. The restoration that gave it its present appearance dates from 1875, when the chapter of Vyšehrad acquired it and had it put in order to a design by the architect Antonín Baum, recovering its Romanesque lines. Inside, 19th-century wall paintings and an altarpiece by František Sequens.

Why does it remain overlooked? Because it is small, set apart from the main tourist route and rarely open: today it belongs to the ecclesiastical chapter of Vyšehrad and is used for worship, not as a museum. The interior can be seen on the occasion of Masses (generally on Saturday mornings and on some weekdays in the late morning or evening) or by guided tour arranged in advance. But the best of it — the compact form, the lantern, the cannonball — is all readable from the outside, at any time.

Getting there

To get there: the metro station is Vyšehrad, on line C (red), from which you reach the entrance to the fortified complex on foot in about ten minutes, passing through the ancient gates. The rotunda is at the address V Pevnosti, Praha 2, inside the Vyšehrad park, which is freely accessible and easily walked. It is worth combining it with a full tour of the hill: the ramparts overlooking the Vltava, the basilica, the cemetery and the remains of the medieval buildings. Spring and early autumn are the best times to walk among the meadows and the ramparts without the heat of summer.

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