Museum Moderner Kunst Stiftung Ludwig Wien in Vienna

You're standing at the mumok, or in full, the Museum moderner Kunst Stiftung Ludwig Wien. It sits in the MuseumsQuartier, right in Vienna's historic centre. Take a good look at the building itself. It's a sharp-edged cube, clad entirely in basalt lava. Surrounded by all those elegant Viennese façades, this dark, closed block really stands out. It was designed by the Austrian architects Ortner & Ortner, and it opened on 15 September 2001.