This was originally designed by Sir Giles Gilbert Scott, the architect of Battersea Power Station, and built in two stages between 1947 and 1963.

Much of the original internal structure remained, including the cavernous main turbine hall, which retained the overhead travelling crane.

An electrical substation, taking up the Switch House in the southern third of the building, remained on-site and owned by the French power company EDF Energy while Tate took over the northern Boiler House for Tate Modern's main exhibition spaces.

[6] The history of the site as well as information about the conversion was the basis for a 2008 documentary Architects Herzog and de Meuron: Alchemy of Building & Tate Modern.

The previous year the three existing Tate galleries had received 2.5 million visitors combined.

[8] Tate Modern had attracted more visitors than originally expected and plans to expand it had been in preparation since 2004.

[9][10] The southern third of the building was retained by the French State owned power company EDF Energy as an electrical substation.

[14] In June 2013, international shipping and property magnate Eyal Ofer pledged £10 million to the extension project, making it to 85% of the required funds.

Eyal Ofer, chairman of London-based Zodiac Maritime Agencies, said the donation made through his family foundation would enable "an iconic institution to enhance the experience and accessibility of contemporary art".

[16] The first phase of the expansion involved the conversion of three large, circular, underground oil tanks originally used by the power station into accessible display spaces and facilities areas.

Sir Nicholas Serota commented, "Len Blavatnik's enthusiastic support ensured the successful realisation of the project and I am delighted that the new building now bears his name".

The western end consists of a gentle ramp down from the entrance and provides access to both sides on level 0.

Since the Tate Modern first opened in 2000, the collections have not been displayed in chronological order but have been arranged thematically into broad groups.

[37] The arrangement was: The Turbine hall, which once housed the electricity generators of the old power station, is five storeys tall with 3,400 square metres of floorspace.

In this time the company provided £4.4m sponsorship in total including a renewal deal of £2.2m for a period of five years agreed in 2008.

[44] The artists who have exhibited commissioned work in the Turbine Hall as part of The Unilever Series are: In 2013, Tate Modern signed a sponsorship deal worth around £5 million with Hyundai to cover a ten-year program of commissions, then considered the largest amount of money ever provided to an individual gallery or museum in the United Kingdom.

[53] A sell-out show by Kraftwerk in February 2013 crashed the ticket hotline and website, causing a backlash from the band's fans.

[54] Two wings of the Boiler House are used to stage the major temporary exhibitions for which an entry fee is charged.

[55] A 2014 show of Henri Matisse provided Tate Modern with London's best-attended charging exhibition, and with a record 562,622 visitors overall, helped by a nearly five-month-long run.

Other locations that have been used in the past include the mezzanine on Level 1 and the north facing exterior of the Boiler House building.

[60] In addition to exhibition space there are a number of other facilities: The closest station is Blackfriars via its new south entrance.

Other nearby stations include Southwark, as well as St Paul's and Mansion House north of the river which can be reached via the Millennium Bridge.

The lampposts between Southwark tube station and Tate Modern are painted orange to show pedestrian visitors the route.