A mesa is a flat-topped hill or mountain with steep sides, found mainly in dry regions like the American Southwest. The word comes from Spanish and means “table,” which makes sense when you see one: a mesa looks like a giant table rising from the desert floor, with a broad, level top and cliffs dropping down on all sides.

Mesas form over millions of years through erosion. They start as flat layers of rock, but wind and water slowly wear away the softer rock around them, leaving behind the harder rock on top like a protective cap. The steep sides keep eroding, but the flat top stays relatively safe. Eventually, if erosion continues long enough, a mesa might shrink into a butte (pronounced “byoot”), which is similar but smaller and narrower.

You can see spectacular mesas throughout Arizona, New Mexico, Utah, and Colorado. Mesa Verde in Colorado is famous for ancient cliff dwellings built by the Ancestral Puebloan people right into the mesa's sides. Many mesas in the Southwest have spiritual significance to Native American tribes and have served as landmarks for travelers for thousands of years.

The word “mesa” also appears in place names across the Southwest, like Mesa, Arizona, one of the largest cities in the United States.