The rotunda of St Martin is the largest and oldest preserved rotunda in Prague. It was built in the second half of the 11th century. It has escaped demolition several times in its history. During the Thirty Years’ War it was used as a gunpowder store. The cannonball embedded in the façade to the right of the window is a reminder of the Prussian rampage in 1757. The rotunda is now used for religious purposes by the Vyšehrad ecclesiastical chapter.
Guided tours by appointment only.
The rotunda was built in the 2nd half of the 11th century, and it was turned into gun powder storage when the fortress was established. In 1841 it was threatened by the planned communication between the New Town and Pankrác, but count Karel Chotek managed to preserve the Romanic rotunda. In 1875 it was purchased by the Vyšehrad canonry and was restored according to a project of architect Antonín Baum. Antonín König and Jan Heřman painted the interior wall paintings, and František Sequens painted the altar painting. Today’s appearance is the result of several repairs. The rotunda’s internal diameter is 650 cm; the apse is 220 cm deep, and the walls are 95 – 97 cm thick. Above the portal created in a pseudo-Romanic style, there is a canon ball walled in to commemorate the Prussian siege of Prague in 1757. The entrance was originally to the West. The rotunda has a so called lantern on the roof, edged with a gold-plated cross with a half-moon and the sun.