The Archbishops of Mainz had the Mildenburg castle built at the end of the 12th century to secure their powerful position and to serve as a customs office. Around 1200, the castle keep was added, the first official reference dates to 1226. Rather diverse periods in history affected the castle: extending, capturing, damaging and reconstructing.
Mildenburg the seat of the Oberamtmann, the Archbishop's local administrator until 1803. It then passed to the Princes of Leiningen before Carl Gottlieb Horstig purchased it in 1825. It now houses a museum of icons and contemporary art. The castle’s inner ward once held the Teutonenstein, a 5 m-tall sandstone column found on Greinberg, the inscription of which is still a puzzle to this day.
The Chapel of St. Martin is the only completely preserved Romanesque building in Vyšehrad and one of the oldest in Prague. In was built around 1100 in the eastern part of the fortified outer ward. Between 1100 and 1300, the Rotrunda was surrounded by a cemetery. The building survived the Hussite Wars and was used as the municipal prison of the Town of the Vyšehrad Hill.
During the Thirty Years’ War, it was used as gunpowder storage, from 1700 to 1750, it was renovated and reconsecrated. In 1784, the chapel was closed passed to the military management which kept using it as a warehouseand a cannon-amunition manufacturing facility. In 1841, it was meant to be demolished to give way to the construction of a new road through Vyšehrad. Eventually, only the original western entrance was walled up and replaced with a new one in the sountren side. The dilapidating Rotunda subsequently served as a shelter for the poor.