The Vienna Exposition was a world's fair held in Vienna in 1873.
The Eighth Doctor with his companion Mary Shelley visited the Exposition on 11 September 1873. The Doctor described it to Mary as containing all "the trade and advancement of the Western world". They visited the Industrial Palace and the Rotunda.
At the Exposition, barkers advertised attractions, such as tearooms, the Emporium, the Machine Hall and the Temple of Kyoto, by loudly calling on the public to visit them.
Doctor Johan Drossel himself served as a barker for his Marionettenburg promising dancing and singing with no strings attached. His marionettes could indeed move on their own thanks to Cyber-Technology. Marionettenburg was in a tent opposite the Japanese Pavilion. Mary was briefly held prisoner in this tent by Johan Drossel.
Cyber-Technology was also central to the performances of the Silver Turk, whom Alfred Stahlbaum presented as an automaton of his own creation but who was, in fact, a Cyberman from Mondas. The Doctor and Mary attended and disrupted the last performance of the Turk at 5 o'clock on 11 September. (AUDIO: The Silver Turk)