Having spent an extended Easter Weekend at Vienna, I just had to visit the Heeresgeschichtliches Museum (HGM) [lit. "Museum of Army History", although "Museum of Military History" is more accurate] on which I had missed out last time.
Completed in 1856, it is the oldest purpose-built military museum in existence. I can highly recommend a visit to all members.
Fore more information on the HGM and its history, see:
Heeresgeschichtliches Museum (German language Wikipedia article with numerous photographs, so definitely worth looking at even for non-German speaking members)
Museum of Military History, Vienna - Wikipedia, the free encyclopedia (very brief English language Wikipedia article)
HGM (The museum's official website)