This remarkable photograph shows the inside of the Shaftesbury Memorial Fountain in Piccadilly Circus — best known for the statue of 'Eros' that normally sits on top.
In 1925, the statue was removed to allow construction of the subterranean tube ticket hall. The base remained in place for a while. Bizarrely, one of the main service shafts was sank within the base, as can be seen in this photograph from 1925.
Eros sat out the construction work in Embankment Gardens, before returning to Piccadilly Circus in 1931. Sadly, the monument was re-erected in a slightly different location. Wouldn't it have been more fun to have kept the access shaft as a secret entrance to the tube?
Image from The Sphere, 11 March 1925. Found in the British Newspaper Archive. Copyright Illustrated London News Group. Pedants' note: we know the statue isn't really Eros, thank you.