Shibboleth by Doris Salcedo

Shibboleth is a Biblical reference to a dark moment of violence, and this work invokes just that imagery. Viewers are forced to stand on one side of the crack or the other, asked to peer into the depths and wonder just what the point is. The crack has since been filled, but will always be visible in the floor. First photo is by Garrett Coakley, second is by Nuno Nogueria; both photos from the Tate Modern website.