Johannisburg Palace (Schloss Johannisburg) is one of the most important Renaissance palaces in Germany, a monumental red sandstone structure rising above the River Main. Built in the early 17th century for the Archbishop-Elector of Mainz, it follows a regular courtyard plan with four corner towers that gives it an architectural clarity rare in German palatial architecture of the period.
The interior houses a gallery of Dutch and Flemish paintings from the 17th century — Rubens, Jan Brueghel, and others — which constitutes one of the better secondary art collections in Bavaria. The palace apartments can also be visited. But the most surprising element is the Cork Model Collection in the south wing — a set of extraordinarily detailed models of ancient Roman monuments made entirely from bottle cork. The palace grounds offer good views over the Main river.