Now, meander back to Albertinaplatz where you admired the Danubius Fountain. Look for an archway gate into Burggarten at the corner of Goethegasse and Hanuschgasse. This Art Nouveau greenhouse is Palmenhaus. Inside the Palm House is a quaint restaurant. The unique feature is hundreds of butterflies fluttering among exotic plants and trees in the Imperial Butterfly House. You will enjoy the Palm House experience as much as Emperor Franz Joseph I did when it opened in 1906. An even grander experience is awaiting you at the Palm House at Schönbrunn Palace, the summer residence of the Habsburg Monarchy.