...that there are only two stations on the London Underground containing all 5 vowels? Namely, Mansion House and South Ealing. South Ealing is the only with all the vowels exactly once.
...that St. John's Wood is the only London Underground station to have no letters in common with the word mackerel? The same is also true for the words paperclip and algebra.
...that at least 84 London Underground stations are unique in having no letters in common with an English word? Other examples include wavelength with Oxford Circus, and photocopying with Russell Square.
...that the ticket hall at Bank tube station is partly built in the crypt of Nicholas Hawksmoor's church, St Mary Woolnoth.