Interns at Barkley, a Kansas City, Mo.-based marketing agency, get to work in the company’s historic downtown building, which was the former worldwide headquarters for TWA when Howard Hughes owned the airline. A 30-foot-tall rocket -- placed there by Hughes -- still adorns the roof. Interns are allowed rooftop access, which features a barbecue grill, pool, and ping pong tables, as well as an extensive art collection.