The Dolomites are made of dolomite, the rocky remnants of coral reefs that thrived in ancient shallow seas. The Dolomites’ claim to fame is not great height: the tallest peak in this part of the Italian Alps, Monte Marmolada, reaches up only 10,964 feet (3,342 meters). What makes the Dolomites memorable is their incredibly bold contours, with stark, sheer-walled massifs rising straight up from gently inclined lower slopes.
The contrast is especially striking in winter, when snow blankets the valleys and slopes but not the somber walls of stone. Looming against the horizon are massive rock formations that resemble needles, spires, castles, and fortresses. Saw-toothed ridges tower over distant valleys, while vertical walls rise straight up for 3,300 feet (1,000 meters) and more.
The dramatic contours of the Dolomites attract rock climbers and walking tours from all parts of the world. Intersecting the mountains are a variety of well-marked trails for every level of expertise. Some of them, accessible by chair lift or cable car, are equipped with built-in handholds, ladders, and other safety features. But a few trails, especially in the Brenta (the rugged southwestern part of the range), are more challenging. Winding across glaciers, they require the use of ice axes, crampons, and other specialized mountaineering equipment.
A visitor trekking across a glacier in the Dolomites may find it hard to believe that the mountains originated in a warm, shallow sea. Some 200 million years ago water covered the region, and a coral reef developed atop much older beds of shale and marl (a clayey rock). Over the millennia the coral was compressed into a distinctive type of limestone that contains magnesium. Known as dolomite, it was named after the 18th-century French geologist Deodat Dolomieu, who first described the rock. Dolomite occurs elsewhere in the Alps and in many other places around the globe, including parts of the American Midwest and some places in the Appalachian Mountains.
During a period of mountain building that began 65 million years ago, the Dolomites were uplifted along with the rest of the Alps. Many believe that the Alps formed as a result of the movement of continents—specifically when two great landmasses, Africa and Europe, collided and their margins were heaved upward into crumpled mountainous relief.
Even as the mountains were rising, the forces of erosion began their work of wearing down. Valleys developed where the softer, more easily eroded shale and marl were exposed. The harder dolomite, in contrast, wore away much more slowly. As a result, great masses of dolomite remain more or less intact, forming the stark massifs that now typify this part of the Alps.
The human history of the Dolomites is as intriguing as the landscape itself. Ruled by Rome for hundreds of years, the mountain people developed their own version of Latin—a language called Ladin that is still spoken by some of the residents. Eventually the region became part of Austria, and German took over as the official language—until the area was ceded to Italy at the end of World War I. As a result, many of the mountain features now bear both Italian and German names Torre Undici is also called Elferturm (both names mean “Eleventh Tower”), Croda Rossa is Rotwand (“Red Wall”), and Val Sasso Vecchio and Altensteintal both refer to the same “Old Stone Valley.” But by whatever names, the formations all contribute to the scenic beauty that makes the Dolomites a popular tourist resort around the year.