Between 1706 and 1711, a hunting castle was built on the foundation walls of the former monastery in Ettersburg.
After the beginning (1775) of the reign of Carl August (1757-1828), Anna Amalia (1739 - 1807) chose Ettersburg Castle as her summer residence. It was thanks to her creativity that an attractive park was laid out around the Castle. She designed it in the style of the time, with wooded niches, a hermitage, a natural theatre, an outlook pavilion with a surrounding balcony at Hottelstedter Ecke, inscriptions, sculptures, busts, stone seats, etc.
Anna Amalia, who was devoted to the arts, had a theatre fitted in the ballroom of the Old Castle, where the performances of the amateur theatre, which had had no permanent venue since the castle fire in 1774, were held. The arts moved into Ettersburg. Numerous famous people, like Johann Wolfgang Goethe, Friedrich Justin Bertuch, Johann Gottfried Herder, Corona Schröter, Christoph Martin Wieland and many more, were guests at Ettersburg Castle.
When Anna Amalia looked around for new locations and finally succumbed to the charm of little Tiefurt Castle, Ettersburg Castle sank into oblivion.
Duke Carl August visited the Castle more frequently and again fitted it up as a hunting castle. He had his rifle cabinet moved from the Town Castle to the former Theatre Room of the Old Castle. This room has since been called the "Rifle Room". But the turmoil of war did not pass Ettersburg by unharmed. There was destruction to the building and some of Duke Carl August's significant rifle collection, which had included a number of rare items, was stolen.
It was not until Carl Friedrich and his wife, Grand Duchess Maria Pavlovna, that Ettersburg Castle was discovered anew and used as a summer residence, after completion of some renovation work and partial refurbishing.
Upon abdication of Wilhelm Ernst, the last Duke of Weimar-Saxe, Ettersburg Castle passed into the ownership of the State of Thuringia in 1919.