A pavilion in the style of a giant spinning top has been unveiled in London's Kensington Gardens.
The temporary structure was designed by Olafur Eliasson - known for his giant sunset at the Tate Modern art gallery.
It stands near the Serpentine Gallery and was jointly created with Norwegian architect Kjetil Thorsen.
Visitors will be able to climb a wide, spiralling ramp to a viewing area as well as attend a series of talks, films and performances until 5 November.
The tradition of commissioning an architect to create a pavilion every year began in 2000.
It has featured the work of British architect Zaha Hadid, Daniel Libeskind and designers Rem Koolhaas and Cecil Balmond who created last year's balloon-like structure.
This year's summer programme features performances and talks with artists, architects, and academics, as well as a series of public experiments by scientists on sound, light and colour.