The tower was divided into seven floors of different heights and uses. Only after the exhibition in 1908, were these rooms gradually expanded. On 15 May 1909, the rooms of the Grand Duke (Fürstenzimmer) on Levels 4 and 5 were completed.

The Wedding Room
The artistic decorations of the rooms of the Grand Duchess in Level 5, the so-called “Hochzeitszimmer” (Wedding Room) were financed by donations. A frieze by Philipp Otto Schäfer was painted above an encircling wall panelling in elm wood. The 4.40 m high room has a flat, coffered, gilded stucco ceiling. The floor was designed with a geometric pattern in marble or terracotta.

The Room of the Grand Duke
The room of the Grand Duke on Level 4 had a height of 6.70 m, with a completely painted barrel vault. Depicted are in a consecutive pattern snail shells and meandering lizards. In the keystone of the arch the Grand Duke’s initials EL are depicted within a golden crown. The two wall surfaces were painted in casein paint directly onto the plaster by artist Fritz Hegenbart and depict an allegorical image on a blue background.

The wall panelling with marquetry inlays cover the bottom half of the walls, up to the windows. The oak flooring was laid in a herringbone pattern. A lawyer from Cologne donated the funds for the room.