Mountain chains are long chains of mountains that form a continuous line. The term 'SIERRA' refers to a mountain RANGE in Spain and Portugal, while the ALPS are a mountain RANGE in Central Europe. A RIDGE is a long, narrow elevation of land that runs between two valleys or along the top of a mountain. A RANGE is a group of mountains that are close together and form a line. Finally, a cordillera is a large chain of mountains that stretches across a continent. All of these terms refer to mountain chains, which are long chains of mountains that form a continuous line.