<p>Young Palestinians turn a battered Gaza Strip wall into a combination gym and circus. Like parkour enthusiasts around the world, the athletes treat a city as one big obstacle course. The goal of the noncompetitive sport is to find the fastest way from point to point, often by climbing, jumping, running, and rolling. (See our picks for the <a href="http://adventure.nationalgeographic.com/2009/05/top-ten-parkour-videos-text">top ten extreme parkour videos</a>.)<strong></strong></p><p><strong>Why We Love It</strong></p><p>"A graphic and playful image, this photograph captures a light-hearted moment, juxtaposed against a wall that [evokes] the long term conflict in the Gaza Strip. Dynamic and graceful, the parkour participants move our eyes around the frame—a human pinball machine, frozen for a moment."<em>—Sarah Polger, senior photo editor</em></p><p>"This image keeps my eyes circling around the composition repeatedly, intrigued by every element in the frame. The movement in the scene is not only exciting but also tense, as you wonder how and where the kids will land their training stunts on what looks like an unforgiving terrain."<em>—Ben Fitch, associate photo editor</em></p>