Which canyon in Arizona is a UNESCO World Heritage Site?

The Grand Canyon is the canyon in Arizona that is recognized as a UNESCO World Heritage Site.

Carved primarily by the Colorado River, the Grand Canyon cuts through the Colorado Plateau and exposes layers of rock recording nearly two billion years of geological history. Its immense scale is the result of uplift, erosion, weathering, and river incision over millions of years. The canyon reaches about 1.5 kilometres in depth and stretches roughly 445 kilometres.

UNESCO inscribed Grand Canyon National Park as a World Heritage Site in 1979. The designation recognizes both the canyon’s extraordinary geological record and its importance for understanding long-running Earth processes. Its cliffs, mesas, buttes, and rock strata also create habitats ranging from desert environments near the river to cooler woodland around the rims.

A frequent mix-up is confusing the Grand Canyon with other famous American landscapes. Yosemite Valley, Zion Canyon, and Bryce Canyon are spectacular sites, but they are not the UNESCO property identified by this question. The World Heritage designation applies specifically to Grand Canyon National Park, not to every canyon in Arizona.