The Ottoneum was built by Landgrave Moritz (1592–1627) between 1604 and 1606. It was the very first “fixed” theatre building on the European continent; its architect was Wilhelm Vernukken. The theatre troupes voyaging from court to court were for the first time able to play to a “house”, which soon replaced the travelling theatres customary until then.

Similar to the Marstall and the Zeughaus, the Ottoneum is also an example of the so-called “Weser-Renaissance”, the northern German variant of this epochal style. The building’s heyday as a theatre ended with the 30-Year-War. In 1696, Landgrave Karl ordered Paul du Ry to undertake encompassing modification of the building, in order to be able to move his valuable collection of art and natural artefacts from the Marstall. Until 1779, the year of completion of the Museum Fridericianum, the Ottoneum housed the court collections and served as the site of scientific experimentation (foundation of the `Collegium Carolinum´ in 1709; observatory). In 1888, after an interruption lasting 100 years, the building is rededicated as the “Prussian Museum of Natural Artefacts”, and in 1929, is renamed municipal “Natural Science Museum”.

During WWII, both collection and building are severely damaged; rebuilding took place between 1949 and 1954. The museum’s natural science collection goes back to the baronial “Art Chamber” of the 16th century and is therefore one of the oldest natural science collections in Europe, and the oldest in Hesse. Significant exhibits are, for example, the so-called Wooden Library and the “Goethe-Elephant”.

Somewhat recessed from the central Friedrichsplatz, the building is still part of the surrounding ensemble. The entrance on the north-eastern side opens on to the cobbled Papinplatz.

Neighbouring locations: State Theatre Kassel, Museum Fridericianum , Zwehrenturm