what is a mountain pass
A mountain pass (also called a gap, saddle, or col) is a passage over a mountain range. They typically occur in valleys between mountain ridges, in low points along mountain watersheds or just the lowest point on a mountain ridge between two peaks. They can be relatively short in length (the width of a ridge) or they can be valleys many miles long. Mountain passes are often the location where roads and railways are built to get through the mountains. Many of them have become famous throughout history for their importance in trade and commerce.