Sierras are mountain ranges. Mountains in Spanish-speaking and Portuguese-speaking regions often have "sierra" in front of their names, such as the Sierra del Sur in southern Mexico or the Sierra Negra in Ecuador.

Sierra is a Spanish word that means "saw." The peaks of sierras are often rocky and jagged, like the rugged teeth of a saw blade.

In the United States, the Sierras or the High Sierra usually refers to the Sierra Nevada, a craggy mountain range that borders the U.S. states of California and Nevada.

The African country of Sierra Leone was named by European explorers in the fifteenth century. Sierra Leone means lion mountains in Italian. The name comes from the Loma Mountains and the lions native to the area.

Sierras are often popular places for skiing and snowboarding in the winter or camping and hiking in the summer. The Sierra Club, one of the most important environmental preservation groups in the United States, was founded in 1892 by the conservationist John Muir.