Let's discuss modern architecture sights worth seeing. In particular, the lesser known projects. Everybody knows about the Guggenheim, Empire State Building, etc. By modern, let's say 1900 and later, so that includes Art Deco. I will be in Spain (the entire country) and Berlin this July. In Spain, I'm particularly interested in looking at some of the works of Santiago Calatrava, as he is my favorite modern architect. If there is anything else modern worth looking at, I'd love to know. For Calatrava, I'm just looking at the entries in his Wikipedia article. If there are others not mentioned there, I'd also like to know. I'll start with some reviews: Berlin Crown Prince Bridge - Calatrava. OK, not that impressive Oberbaum Bridge - Calatrava. He just did the refurbished middle-section of the bridge. Not worth seeing unless you have time to kill. DZ Bank - I have mixed feelings about Gehry. This one just looked like a pretty cool giant sculpture, and not an architectural work. Dutch Embassy - Koolhaas. Decent, bizarre for the sake of bizarre, like a lot of modern architecture. Watch out for the barking dog. Reichstag - Awesome, I love Foster. Worth the wait in line. Federal government complex - Pretty cool.