The highlight of Joseph’s Square is Prunksaal. The State Hall was added to Hofburg Palace in 1723. Inside of this Baroque wing is the Austrian National Library, originally called the Imperial Court Library. Many of the books and manuscripts date back to the Middle Ages. A few are from the 4th century. The library also registers all works of contemporary Austrian authors. Even if you have no interest in libraries, step inside. You will be awed by the frescos and 65 foot dome.