No one knows how to select a fabulous backdrop quite like the Kardashian-Jenner clan. And for their Holiday 16 Kendall + Kylie campaign, that's just what Kendall and Kylie Jenner did—and we found out where they shot it. As residents of Los Angeles, we instantly recognized the façade of the building (pictured above) as belonging to the iconic Greystone Mansion. The palatial 1930s estate, which took three years to construct, is set inside a park in Beverly Hills by the same name. And the best part: It's totally free and open to the public. We've actually visited the park on a number of occasions, and it's stunning. It's also regularly empty—it really seems like one of L.A.'s best-kept secrets.