A new entrance at Knightsbridge Tube station, together with three new lifts, has increased accessibility close to some of London's tourist hotspots.
The new step-free route re-introduces some parts of the west London station shut for nearly 100 years.
The entrance on Hooper's Court features three 17-person lifts, which provide street-to-platform access to the Piccadilly line for the first time at the station.
Knightsbridge sees more than 13 million journeys each year as people travel to destinations such as Harrods, Harvey Nichols and Hyde Park.
Knightsbridge is the 93rd station on the Tube network to offer step-free access, Transport for London (TfL) said.
Travellers who do not need step-free access are encouraged to continue to use the main entrance to the station on Brompton Road.
As part of a redevelopment of the building above, parts of the station that have been out of use since the 1930s due to escalators being installed were re-opened.
TfL has restored architectural features of its façade while modernising other areas.
More than a third of Tube stations are now step-free, TfL said. It hopes that half of the network will be by 2030.
