in each. Space between these wings is also used for smaller galleries on levels 2 and 4. The Boiler House shows art from 1900 to the present day. The Switch House has eleven floors, numbered 0 to 10. Levels 0, 2, 3 and 4 contain gallery space. Level 0 consists of the Tanks, spaces converted from the power station's original fuel oil tanks, while all other levels are housed in the tower extension building constructed above them. The Switch House shows art from 1960 to the present day. The Turbine Hall is a single large space running the whole length of the building between the Boiler House and the Switch House. At six storeys tall it represents the full height of the original power station building. It is cut by bridges between the Boiler House and the Switch House on levels 1 and 4 but the space is otherwise undivided. The western end consists of a gentle ramp down from the entrance and provides access to both sides on level 0. The eastern end provides a very large space that can be used to show exceptionally large artworks due its unusual height. Exhibitions Collection exhibitions The main collection displays consist of 8 areas with a named theme or subject. Within each area there are some rooms that change periodically showing different works in keeping with the overall theme or subject. The themes are changed less frequently. There is no admission charge for these areas. As of June 2016 the themed areas were: Start Display: A three-room display of works by major artists to introduce the basic ideas of modern art. Artist and Society In The Studio Materials and Objects Media Networks Between Object and Architecture Performer and Participant Living Cities There is also an area dedicated to displaying works from the Artist Rooms collection. History of the collection exhibitions 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. Prior to the opening of the Switch House there were four of these groupings at a time, each allocated a wing on levels 3 and 5 (now levels 2 and 4). The initial hanging from 2000 to 2006: History/Memory/Society Nude/Action/Body Landscape/Matter/Environment Still Life/Object/Real Life The first rehang at Tate Modern opened in May 2006. It eschewed the thematic groupings in favour of focusing on pivotal moments