PERU: MACHU PICCHU

Get a reverse angle on Machu Picchu from the 8,920-foot summit of Huayna Picchu, the looming peak in all those memorable images of the Inca site. Only 200 hikers a day are permitted to make the two-hour round-trip trek. Go slow while descending the notoriously steep “stairs of death” near the top.

JORDAN: PETRA

Sculpted from soaring sandstone cliff walls more than two millennia ago, the ancient Nabataean city is one of the world’s most famous archaeological sites. Hike about 800 steps up to Petra’s massive monastery for top-of-the-rock vistas of the Wadi Arabah desert.

INDONESIA: BOROBUDUR

On the island of Java, Maha-yana Buddhist pilgrims climb the 95-foot-high, multitiered structure (the single largest Buddhist temple on Earth) as a symbolic journey to enlightenment. Apex views of surrounding volcanoes are breathtaking, but the nearly 3,000 bas-reliefs deserve a closer look.

GREECE: ACROPOLIS

Crowned by the fifth-century b.c. Parthenon, Athens’s hilltop citadel is a complete ancient Greek monumental complex still in existence. Walking up takes 15 to 20 minutes. For a less steep climb, enter on the southeast side near the Acropolis Metro stop.

CHINA: GREAT WALL

Built over a period of 2,000 years, the mother of all border walls (made up of multiple segments) is a tangible link to imperial China. Walk in the footsteps of emperors, and see well-preserved Ming dynasty–era watchtowers on the six-mile Jinshanling section, 2.5 hours northeast of Beijing. Start at Zhuanduokou Pass for hikes that can last 1.5 to three hours.

SRI LANKA: SIGIRIYA

Towering 590 feet over the surrounding countryside in central Sri Lanka, the granite monolith known as Lion’s Rock (colossal stone paws still flank the staircase) is capped by the ruins of a fifth-century royal palace. Don’t look down on the vertigo-inducing climb (about 1,200 steps) to the summit

CROATIA: PLITVICE LAKES NATIONAL PARK

An emerald Eden and UNESCO World Heritage site, Plitvice has 16 terraced lakes linked by boardwalks, streams, and tumbling cascades. Hike through a canyon and a cave to the base of the national park’s tallest (256-foot-drop) waterfall on the six-to-eight-hour north entrance walking tour.

KENTUCKY: MAMMOTH CAVE NATIONAL PARK

Snaking beneath central Kentucky’s hills is the world’s longest known cave system. So far, more than 400 miles have been explored. On the two-hour Domes and Dripstones Tour you’ll go deep—about 280 steps down—into a mammoth underworld of stalactites and stalagmites.

FRANCE: PROVENCE’S LAVENDER ROUTE

Lavender fields fill a summer walk in Provence’s Lubéron region with color and fragrance. Several hiking routes (called sentiers) wind through the area. Our favorite fields are at Sénanque Abbey, where the monks’ photogenic rows of lavender draw crowds. Go early or late to avoid the tour buses.

MADAGASCAR: AVENUE OF THE BAOBABS

Some two dozen behemoth baobab trees, many towering almost a hundred feet, line this earthen road near the west coast of the island nation of Madagascar. The scene looks straight out of the movie Land of the Lost—and, in fact, these gentle giants, protected since 2007, are 800-year-old survivors of a primordial forest.

LHASA, TIBET: POTALA PALACE

Perched at over 12,000 feet above sea level, the Tibetan architectural masterpiece and former residence of the Dalai Lama is considered the world’s highest altitude ancient palace. Acclimate yourself to the thin air before attempting the more than 400 steps to the top.

JAIPUR, INDIA: AMBER FORT

The imposing 16th-century complex of palaces and temples sits high atop the “hill of eagles” in Rajasthan. A strenuous (there’s an ambulance at the top) 10-minute climb leads up to the fort’s jewel-like mosaics, elaborate courtyards and halls, and the Pink City panorama below.

SYDNEY, AUSTRALIA: SYDNEY HARBOUR BRIDGE

Unleash your inner Spider-Man on the 1,332-step BridgeClimb, which clambers up ladders and traverses catwalks on Sydney’s signature bridge to reach the upper arch, 440 feet above sea level. Short on time or courage? Go just halfway to the top on the 90-minute BridgeClimb Sampler.

More info: nationalgeographic.com

SYDNEY, AUSTRALIA: SYDNEY HARBOUR BRIDGE

JAIPUR, INDIA: AMBER FORT

LHASA, TIBET: POTALA PALACE

MADAGASCAR: AVENUE OF THE BAOBABS

FRANCE: PROVENCE’S LAVENDER ROUTE

KENTUCKY: MAMMOTH CAVE NATIONAL PARK

CROATIA: PLITVICE LAKES NATIONAL PARK

SRI LANKA: SIGIRIYA

CHINA: GREAT WALL

PERU: MACHU PICCHU

JORDAN: PETRA

INDONESIA: BOROBUDUR

GREECE: ACROPOLIS