Tate Modern suffered an 8 per cent drop in the number of visitors during 2013, according to figures released this week.
The Association of Leading Visitor Attractions (ALVA) has published visitor figures for its 197 members across the UK.
Nearly 4.9 million people visited Tate Modern last year, down 8 per cent on the record-breaking 5.3 million figure achieved during 2012.
The fall bucks the overall trend with an average increase of 6 per cent to all ALVA member attractions. Other major London museums and galleries reported strong performance.
The Tower Bridge Exhibition saw a 17 per cent rise in visitor numbers, with 595,000 people visiting the high-level walkways above the Thames.
The attraction has now submitted a planning application for the installation of a glass floor allowing visitors to the upper walkways to see the bridge's bascules lifting.
As expected the Imperial War Museum's main London site in Lambeth Road saw a sharp decline in visitor numbers with just 360,886 through the doors during the half-year it was open to the public in 2013.
The museum is due to reopen fully this summer at the start of the World War I centenary commemorations.