Few places in America inspire as much longing as Havasu Falls — the impossibly turquoise waterfall that has become a bucket-list icon of the Southwest. It lies deep in Havasu Canyon on the Havasupai Reservation, a side canyon of the Grand Canyon so remote it can be reached only on foot, by pack mule, or by helicopter. The Havasupai are the “people of the blue-green water,” and this is their homeland: a hidden desert oasis where waterfall after waterfall pours over red travertine cliffs into pools the color of the Caribbean.

That astonishing blue-green color is no trick of the light. Havasu Creek is spring-fed and saturated with calcium carbonate, which scatters sunlight into the vivid turquoise hue and, over time, deposits as travertine — building the smooth ledges, terraces, and natural dams that shape the pools. The mineral-laden water even rebuilds the falls after floods, which is why the canyon's cascades have shifted and been renamed over the years.

The falls come in a spectacular string below the village. Fifty Foot Falls and Navajo Falls — reshaped by a major 2008 flood and sometimes called Rock Falls — come first, followed by the star of the show: Havasu Falls itself, a roughly 100-foot plunge into a wide, swimmable turquoise pool that ranks among the most photographed sights in the world. Below the campground, Mooney Falls drops nearly 200 feet, the tallest in the canyon, and reaching its base is an adventure in itself: a steep scramble down through carved tunnels and along chains and slick ladders bolted to the dripping travertine wall. Farther on, about four miles past the campground, Beaver Falls tumbles in tiers through a lush grotto, and the truly ambitious can follow Havasu Creek roughly eight miles all the way to its confluence with the Colorado River.

Getting there is a genuine journey. The hike begins at Hualapai Hilltop and drops about 2,000 feet of switchbacks into the canyon, then follows a sandy wash 8 miles to the village of Supai — one of the most remote communities in the lower 48, so isolated that the U.S. mail still arrives by pack mule. From the village it's another 2 miles past Havasu Falls to the campground, which stretches about a mile along the creek between Havasu and Mooney Falls, with drinking water available at Fern Spring. All told it's roughly 10 miles each way, and the climb back out at the end is long and hot.

This is a permit-only destination, and getting one is the hardest part of the whole trip. The Havasupai Tribe requires a reservation for every visitor, and day hiking is not allowed — all permits are for a fixed three nights and four days. Camping permits run about $455 per person for the stay (a lodge in Supai is the pricier alternative), sold only through the tribe's official reservation website. New permits for the year are released on February 1 at 8:00 a.m. Arizona time and routinely sell out within minutes to a virtual line tens of thousands deep; a paid early-access window and a cancellation-transfer system offer other ways in. Do not hike in without a confirmed reservation — visitors without permits are turned around, and there are no walk-ups.

Come prepared and treat the canyon with respect. Summer is brutally hot, so many hikers walk the exposed miles at dawn and carry far more water than they think they'll need. Flash flooding is a serious, recurring danger here — the canyon has flooded and forced evacuations more than once — so watch the weather, camp on high ground, and heed any guidance from tribal rangers. Remember that this is tribal land and a living community, not a park: alcohol and drones are banned, pets should be left at home, and everything you carry in must be packed out. Book far ahead, aim for the milder weather of spring or fall, and Havasu Falls will repay the effort with one of the most unforgettable landscapes on the continent.