In The Case of the Phone Box Murder, while investigating the murder of Hans Muller, Biggles asked Ginger to book for themselves four single rooms at the West Bahn Hotel in Vienna. This was, according to Ginger, one of the largest hotels in Vienna--which was, to Biggles, an advantage as it would make it less likely that new arrivals would be noticed.
The Westbahn hotel is an actual hotel in Vienna. It was first built in 1865, near the Westbahnhof which was at that time the main rail terminus for international trains to Vienna. The Westbahn Hotel is Vienna’s oldest building designed and built specifically as a hotel. Since then the hotel has been renovated and modernized on several occasions although the historic facade has been maintained. It is still operating today as a four-star family-run hotel with 52 rooms and is still popular because of its central location near to the Westbahnhof which is one of the busiest commuter stations in Vienna. Among its heritage features, it claims to have "a calm old vienna style inner courtyard with a historic garden well". It is not clear, though, if 52 rooms would have made it one of the largest hotels in Vienna in the early 1950s.