Tate Modern's Turbine Hall takes visitors to the dark side

Part of the Unilever series, Miroslaw Balka's How It Is invites visitors to explore the pitch-black space inside it Photograph: David Levene

The exterior of How It Is, constructed with steel and held aloft on two-metre-high supports Photograph: David Levene

The title of the installation takes its inspiration from the Samuel Beckett novel of the same name Photograph: David Levene

Miroslaw Balka, the 10th artist to fill the Turbine Hall Photograph: David Levene

One of the two-metre-high supports that hold up the structure Photograph: David Levene

Visitors walk beneath and around the container, which Adrian Searle calls an 'unnerving experience' Photograph: David Levene

The structure almost entirely fills the Turbine Hall. Here it is seen from the side ... Photograph: David Levene

... and the back Photograph: David Levene

Visitors walk underneath the artwork before arriving at the ramp that leads up to its entrance Photograph: David Levene

Adrian Searle judges Balka's work of art to be a success. It 'reveals darkness rather than cloaking it in mystery,' he says. How It Is is at the Turbine Hall, Tate Modern, until 5 April 2010 Photograph: David Levene