Frontier Airlines DEN Terminal flies mostly from Concourse A at Denver International Airport (DEN). Frontier's major hub is in Denver, and the airline operates a number of domestic and international flights from this terminal. The DEN terminal offers guests convenient check-in choices, including as self-service kiosks and staffed counters, as well as a variety of culinary and shopping options to enjoy before flights. Frontier's commitment to economical, efficient travel is clear in its operations here, making it an attractive option for budget-conscious visitors wishing to visit places around the United States and abroad. VISIT US:......See More