Route 66 Turns 100: Here’s Where to Detour for 6 UNESCO World Heritage Sites

Route 66 has always been as much about what lies along the way as where the road leads. For nearly 2,400 miles between Chicago and Los Angeles, the highway passes neon motel signs and old-school diners, desert towns and trading posts, with plenty of reasons to pull off the road.

In 2026, the Mother Road turned 100. Established in 1926 as part of the original U.S. numbered highway system, Route 66 became one of America’s most storied drives before it was officially decommissioned in 1985. Much of the historic road remains drivable today, and its centennial offers a particularly good excuse to follow it—and occasionally leave it behind.

Several worthwhile detours lead to UNESCO World Heritage sites. The United States has 27 of the more than 1,200 World Heritage properties around the globe, and a Route 66 road trip can put travelers within reach of several of them, from ancient Puebloan sites and one of North America’s great pre-Columbian cities to the Grand Canyon and some of Frank Lloyd Wright’s most influential buildings. Here’s how to see them.

Related: Route 66 at 100—Things to Do and Places to Stay

Frank Lloyd Wright’s 20th-Century Architecture: Illinois

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Before Route 66 leaves the Chicagoland area for the long drive west, two buildings offer a look at Frank Lloyd Wright during one of the most consequential periods of his career. Both belong to UNESCO’s eight-site collection of Wright works, inscribed in 2019 for their influence on modern architecture.

In Oak Park, Unity Temple, completed in 1909, was a radical departure from the religious architecture of its era. Faced with a limited budget and a noisy urban site, Wright designed the building to be made with poured concrete, a relatively inexpensive material and associated then more with factories and warehouses than houses of worship. He also brought daylight into the sanctuary from above instead of windows on the walls and arranged the seating around the central space so no one sat far from the pulpit. About 15 miles southeast in Hyde Park, the Frederick C. Robie House shows Wright applying similarly unconventional thinking to a private home. Completed in 1910, it stretches horizontally across its lot beneath dramatic cantilevered roofs, with open, interconnected rooms that helped define the Prairie style.

Related: 12 Frank Lloyd Wright Houses You Can Visit

Cahokia Mounds State Historic Site: Illinois

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Just before Route 66 crosses the Mississippi into St. Louis, it passes within a few miles of what was once the largest pre-Columbian city north of Mexico. Cahokia reached its peak around the 11th and 12th centuries, when thousands of people lived among a sprawling network of neighborhoods, plazas, and monumental earthworks.

The biggest still standing is Monks Mound, a four-tiered earthen structure that covers more than 14 acres and rises roughly 100 feet above the surrounding floodplain. Dozens of other mounds across the site are remnants of a city whose size and organization helped earn Cahokia UNESCO World Heritage status in 1982.

Cahokia Mounds is near Collinsville, Illinois, just east of St. Louis, making it one of the easiest UNESCO detours on the entire Route 66 drive.

Taos Pueblo: New Mexico

Route 66, for its first decade, took a very different path through New Mexico than the one most drivers follow today. The original 1926 alignment curved north from Santa Rosa through Santa Fe before turning south toward Albuquerque; in 1937, the highway was rerouted along a more direct east-west path. Travelers can still drive either alignment today, but choosing the earlier route puts them considerably closer to Taos Pueblo, about 70 miles north of Santa Fe.

At the base of the Sangre de Cristo Mountains, Taos Pueblo is distinguished by its multistory adobe buildings, constructed from earth mixed with water and straw and maintained using those traditional materials for centuries. Unlike many UNESCO sites, this isn’t an ancient settlement preserved for visitors—members of the Taos Pueblo community continue to live here, as they have continuously for more than 1,000 years. UNESCO inscribed it in 1992, recognizing both its adobe architecture and the endurance of Pueblo cultural traditions.

Chaco Culture National Historical Park: New Mexico

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Getting to Chaco Culture National Historical Park takes commitment: The park sits in a remote stretch of northwestern New Mexico, roughly two hours from Route 66, and the final approach includes miles of unpaved road. But once inside the canyon, visitors can walk through massive stone great houses, peer into circular kivas, see petroglyphs carved into sandstone cliffs, and follow traces of an ancient road network that once extended across the region.

Chaco was a major center of Puebloan life between roughly 850 and 1250 C.E., and some of its buildings were oriented to cardinal directions and astronomical cycles. UNESCO designated Chaco Culture a World Heritage site in 1987, recognizing a network that extends beyond the canyon to related sites across northwestern New Mexico.

Grand Canyon National Park: Arizona

Photo by Stig-Ove Petterson

The Grand Canyon is so familiar from photographs that its scale can be easy to underestimate. In person, the canyon stretches as far as 18 miles from rim to rim and drops more than a mile to the Colorado River, with layers of limestone, sandstone, and shale tracing nearly 2 billion years of Earth’s history.

But the canyon isn’t just a record of the distant past. The Colorado River is still carving through the rock, while erosion, weather, and seasonal floods continue to reshape its cliffs, side canyons, and tributaries. That depth also creates strikingly different environments within a single park, from ponderosa pine forests along the South Rim to desert conditions thousands of feet below. UNESCO designated Grand Canyon National Park a World Heritage site in 1979 for that extraordinary geological record, as well as the diversity of plants and animals supported by the park’s enormous range in elevation.

Related: The First-Timer’s Guide to Grand Canyon National Park

Frank Lloyd Wright’s 20th-Century Architecture: California

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Route 66 ends in the Los Angeles area, where one more component of UNESCO’s Frank Lloyd Wright collection sits just off the historic road.

Built between 1919 and 1921 for oil heiress and arts patron Aline Barnsdall, Hollyhock House was intended as the centerpiece of an ambitious arts colony atop Olive Hill. That larger vision was never fully realized, and Barnsdall later donated the house and surrounding land to Los Angeles for public use; today, it anchors Barnsdall Art Park.

The design itself marked a departure for Wright. Drawing on Southern California’s climate and pre-Columbian architecture, he arranged rooms around courtyards and terraces, opening the house to the outdoors. Barnsdall’s favorite flower became a recurring design element, too: An abstracted hollyhock appears in concrete ornament, furniture, textiles, and art glass throughout. For travelers who began Route 66 with Wright’s UNESCO-listed buildings in Chicago, Hollyhock House provides one last architectural connection near the road’s western end.