Baker Street is one of the first stations of the Metropolitan Railway (MR), the world's first subway, opened in 1863. Today it is the station with the most platforms on the entire London Underground network.
Restoration work in 1980 brought the older part of the station back to its original 1863 form. The underground platforms of the Circle line and Hammersmith & City line are the best preserved of the old station. Along the platforms, in addition to the tiles that recall the fictional connection with Sherlock Holmes, there are panels with old plans and photographs of the station.