A metal garden. Made up of cut steel flowers & plants. The vintage, text-book looking botanical specimens are black, if you walk around to the other side, the opposite side of this installation is painted in stunning color.
"The temporary art installation 'Endless Stair' has been erected outside the Tate Modern to launch national design week. It was created by dRMM Architects and inspired by M C Escher's surreal drawings of never-ending staircases. caption at link