Find great value on Frontier Airlines flights from DAY to DEN when you book with CheapOair! The Mile High City is easy to navigate, is a major metropolis, and has great outdoor adventure opportunities. If this is a family trip, take your kids to the Children’s Museum of Denver, the museum has astounding hand-on exhibits to keep your little ones engaged. The Denver Art Museum houses a great amassment of art from all your the world while the Denver Mint gives a detailed account on how coin is made. For a family day out, consider visiting the Denver Zoo that is home to a variety of inhabitants or the Denver Botanic Gardens to spend some time with nature. Book your seats and catch a show at the Denver Center for the Performing Arts or a classic opera show at the Opera Colorado.