The four-winged Castle complex was erected in 1365 as the seat of the Bailiff of the Electorate of Cologne by Archbishop Engelbert von der Mark in Linz am Rhein. Next to Andernach, the city and castle of Linz were the two most important power centres of the Cologne archbishops on the Middle Rhine. Similar to the situation in Boppard, the city castle in Linz was secured against the city and its own citizens, among other things by a moat. The three-storey western wing was added in 1707. At the level of the foundations as well as on the northwestern tower, the late Gothic features can still be made out today. Since the Baroque modernisation, Linz Castle is a closed complex surrounding an inner courtyard.
Today, catering is provided in the interior rooms as well as the historical courtyard. A glass-blowing workshop and the torture chamber make Linz Castle a special tourist attraction.