Before revision: Formation of parallel mountain chains upright=1.2|In this satellite image of the Alps, the snow limit picks out the individual mountain chains The chain-like arrangement of summits and the formation of long, jagged mountain crests – known in Spanish as sierras ("saws") – is a consequence of their collective formation by mountain building forces.
After revision: 200px|A view of the Balkan Mountains chainFormation of parallel mountain chains upright=1.2|In this satellite image of the Alps, the snow limit picks out the individual mountain chains The chain-like arrangement of summits and the formation of long, jagged mountain crests – known in Spanish as sierras ("saws") – is a consequence of their collective formation by mountain building forces.