Sit on the Left side of the plane for the best views on flights from Denver to Barcelona. Left side wins at both ends of the flight — the Rockies on departure and Barcelona city on arrival. Over the Atlantic the views are largely ocean on both sides, so the decisive moments are takeoff and landing where left delivers the most geography.

During takeoff from Denver International (DEN), sit on the Left side for the best views. DEN typically departs east on runway 16R/34L or 17R/35L, then turns northwest toward the route. A left-side seat gives you the Rocky Mountain Front Range running north-south — a dramatic wall of peaks immediately west of Denver. You'll see the entire Front Range from Pikes Peak in the south to Longs Peak in the north as the aircraft climbs and banks. Notable sights include: Rocky Mountain Front Range, Denver metro grid below, Longs Peak (14,259 ft), Mount Evans massif.

When landing at Barcelona (BCN), sit on the Left side for the best views. Barcelona's El Prat airport typically lands on runway 25L/25R approaching from the east over the sea, or runway 07 from the west. On the common eastward approach over the Mediterranean, left-side seats look north directly over the city — you get the Barcelona waterfront, the Eixample grid, and the Tibidabo hill behind the city. Right side faces open sea. Notable sights include: Barcelona waterfront and Port Olímpic, Eixample city grid, Tibidabo hill and Collserola ridge, Montjuïc promontory.

The flight from Denver International (DEN) to Barcelona (BCN) takes Approximately 10 to 11 hours.

After crossing the Rockies, the flight tracks northeast over the Great Plains and the Great Lakes region or southern Canada, then crosses the North Atlantic. The route passes south of Greenland and Iceland, crosses Ireland or northern England, then tracks across France over the Pyrenees before descending into Barcelona. The Pyrenees mountain range crossing near the end of the flight is visible on the left side as a significant east-west ridge system.