We made a quick call into the Tate Modern. I'm not always a great fan of the types of works they exhibit but I did like the Marwan Rechmaoui sculpture of a large tower block built in the early 1970s in Beirut. It was never used for offices but the Lebanese Civil War saw it used as a snipers' post. I saw the building for myself when I was in Beirut in 2008.
Also catching my attention were photos by Bernd and Hilla Becher, especially the water towers.