Britain's Queen Elizabeth II accompanied by her husband The Duke of Edinburgh, and her daughter in law, Catherine, Duchess of Cambridge toured Baker Street tube station today to celebrate 150 years of the world famous London underground.

She looked well as she talked to members of underground staff after recently cancelling a number of engagements because of illness, which is thought to have been gastroenteritis.

Baker street was part of the first Tube line which ran from Paddington to Farringdon, in the centre of London, and opened on January 9, 1863. When it opened it was known as the Metropolitan Railway.

During the visit, the royals were shown around the various aspects of the tube station. Highlights for the Queen included meeting a man dressed as the fictitious world renowned 19th century British detective, Sherlock Holmes, whose author, Arthur Conan Doyle, had live in Baker Street. The monarch was also shown the interior of one of the first underground carriages, and saw what a modern day train looks like.

After the tour, she unveiled a plaque on the side of a train before being given an Oyster card - a travel pass most of her London-based subjects use on public transport. Catherine, Duchess of Cambridge, was also given a card, but also as an addition she was given an official underground 'Baby on Board' badge, which is used to help pregnant women get seats on the underground.