The city's annual Serpentine Gallery Pavilion is a novel concept: Let an architect build a crazy structure in Hyde Park, and if people don't like it, no big deal—it comes down at the end of the summer anyway. The idea seems tailor-made for this year's choice, Frank Gehry, whose wood-and-glass design, pictured, will be his first building in London. Like much of his recent work, it already seems to be inspiring equal amounts of enthusiasm and detraction—even in the same review. For more on the project, check out The Guardian's excellent slideshow of past pavilions by Zaha Hadid, Rem Koolhaas, Daniel Libeskind, and more.