(This article is about the former London building to the east of Regent's Park. For the theatre of a similar name, see Coliseum Theatre.) The London Colosseum was a building to the east of Regent's Park, London. It was built in 1827 to exhibit Thomas Hornor's "Panoramic view of London", the largest painting ever created. The design of the Colosseum was inspired by the Pantheon in Rome. It was demolished in 1874.