Denver, Colorado: This bucolic city nestled in the Rocky Mountains is a great place for those who love the outdoors, but who also crave the draw of a big city. Millennials now make up the largest demographic in the city’s metro population, making it a young and vibrant city with blossoming arts, culture, nightlife, and professional sectors. Distribution and energy jobs are two of the fastest-growing fields in the Mile High City, where young people are drawn to the city’s diverse neighborhoods and affordable rent.