The view’s pretty good from three stories up at Spire—especially when you’re a pooch with energy to burn. Downtown Denver’s posh, year-old high-rise on 14th Street has figured out the secret to selling urban units in the dog-crazy Mile High City: Devote a sunny patch of rooftop space to an open-air bark park on the third floor—splash pool and city view included. According to the developers, Spire may be the fastest-selling high-rise residential project in the country; in just a year, about 240 units have sold—nearly 20 percent to dog owners. So yes, city lovers, you can have your dog and live here, too. No leash required.