Vienna was a city in Austria.
History
Sherlock Holmes and John Watson went on holiday to Vienna on the Orient Express. (NA: All-Consuming Fire)
The Eighth Doctor once left Samson and Gemma Griffin in Vienna while answering a distress signal from his future self. (BFA: Mary's Story) The Eighth Doctor later battled a Bacchanite in Vienna. (ST: The Sorrows of Vienna) Honoré Lechasseur and Emily Blandish once travelled back in time to Vienna to ensure that Adolf Hitler was admitted into the Vienna Academy of Fine Arts. (TN: The Sideways Door) Toby the Sapient Pig was grown in a bell jar in Vienna. (BFA: Year of the Pig) In 2100, the Fifth Doctor dropped Techu off in Vienna. (ST: Leap Second)