The Willy Brandt Berlin Brandenburg International Airport was supposed to open in 2012, but it has been delayed repeatedly and is now set to open in 2017. The cost overruns and delays have made the airport the butt of frequent jokes. Sean Gallup/Getty Images hide caption

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Refugees line up to apply for asylum at a reception center in Berlin, Germany. Figures released last week showed that about 180,000 asylum applications were filed in the first six months of 2015, more than twice as many as in the same period last year. Markus Schreiber/AP hide caption

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Berlin's Humboldt University — named for its founder, the 19th century philosopher and linguist Wilhelm von Humboldt, and his brother, naturalist Alexander von Humboldt, pictured here — is one of several German universities attracting U.S. students. More than 4,000 Americans are studying in German universities. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

Berlin's Humboldt University — named for its founder, the 19th century philosopher and linguist Wilhelm von Humboldt, and his brother, naturalist Alexander von Humboldt, pictured here — is one of several German universities attracting U.S. students. More than 4,000 Americans are studying in German universities. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

Marchers carried a multicolor flag during Warsaw's annual gay pride parade earlier this month. Poland prohibits gay marriage but activists say attitudes toward gays have improved in recent years. Alik Keplicz/AP hide caption

itoggle caption Alik Keplicz/AP