Tate Modern is home to a new artwork - artificial fog.
Japanese artist Fujiko Nakaya has installed a cloud of mist, described as a "fog sculpture", outside the gallery as part of a new "live" exhibition programme.
The 83-year-old artist, whose father is credited with making the first artificial snowflakes, has worked since the 1970s to develop a system to disperse water vapour at high pressure.
She has previously installed fog sculptures at Frank Gehry's Guggenheim Museum in Bilbao, the Grand Palais in Paris and Philip Johnson's Glass House in Connecticut - but this is her first London fog sculpture.
Nakaya first became interested in fog after painting clouds.
She said: "In the modern age, fog has a bad name because of smog. But in the romantic era it was in poems and paintings, in art.
"This is a nice fog for people to enjoy.
"In the sun it looks whiter and shiny, if it's rainy it spreads all over and when it's windy it goes up in the sky," she told the Press Association.
"At first people are a little scared because they can't see. After that they like to get water on them."
Other works as part of the BMW Tate Live Exhibition: Ten Days Six Nights programme include a room filled with potted and hanging plants, and live dance.
Performances by Nakaya's long-term collaborators, such as dancers and drummers, will take place in the fog, which is being pumped out by Tate Modern's new Switch House extension.
The installation is part of a group exhibition in and above Tate Modern's underground tanks - the huge subterranean concrete containers originally built to hold the fuel for Bankside Power Station.
The BMW Tate Live Exhibition: Ten Days Six Nights runs from March 24 to April 2.