Miroslaw Balka at Tate Modern: "How It Is" Pitch black Chamber

It is the work of Polish artist Miroslaw Balka who says entering the darkness could evoke a variety of responses in visitors, from fear to a bizarre feeling of comfort.  

It is mounted on supports two metres high, so that, if you wish, you can walk under it without crouching. But if you do so, you’ll find that having several tons of steel held up by thin supports just above your head feels so oppressive that you’ll soon want to escape. But there is no escape.