A member of the National Park Service, second from left, leads Malia Obama, President Barack Obama, first lady Michelle Obama, and Sasha Obama, on a tour of Carlsbad Caverns in Carlsbad Caverns National Park, in Carslbad, N.M., on Friday, June 17, 2016. The Obama family is traveling to Carlsbad Caverns National Park to celebrate the 100th anniversary of the creation of America's national park system. (AP Photo/Jacquelyn Martin)

Question: Which national park is your favorite?

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