The Royal Aquarium

In Florodora, the comic character Professor Tweedlepunch repeatedly introduces himself as being a Phrenologist "from the Royal Aquarium, London". Originally we had thought that this was a simple humorous non sequitur. Why in the world would a phrenologist be from an aquarium? So, we had originally thought it was like saying you were a snowplow driver from Tahiti.

BUT, it turns out that the Royal Aquarium was an actual place in Victorian London, designed as an aquarium in 1876, but never (almost) used as such. Originally having tanks and an elaborate system of pipes and many other multi-purpose rooms, almost immediately it ran into operating difficulties, but did once manage to display a dead whale.

By the 1890s, the Aquarium had acquired a risqué reputation, with unaccompanied ladies promenading through the hall in search of male companionship. It contained a legit theater which was mostly used as a music hall and for circus and other exotic entertainments. A natural place for a dubious sham phrenologist-cum-detective to claim to hail from, isn't it?

There are two other interesting Savoy Opera connections: The Royal Aquarium included a theater, the aptly named Aquarium Theatre. It had an unusually large Grand Organ whose installation and construction in 1877 was supervised by none other than Arthur Sullivan. In its opening year, one of the plays produced was an adaptation of Great Expectations by W. S. Gilbert.

Still in existence when Florodora was written in 1899, The Royal Aquarium was demolished in 1903, though the Aquarium Theatre stood until 1907. It is immortalized in Florodora. You can read all about it on Wikipedia.