If a traveller from another planet wanted to visit some of the Earth’s greatest landscapes, you might diplomatically send him to Nepal’s Himalayas for icy mountains, Tanzania's Serengeti for endless plains, Brazil’s Amazon for lush rainforests, Australia’s Gold Coast for beaches and the United States’ Yellowstone for volcanic splendour. Or, you might whisper, “Skip all that and just spend two weeks walking around New Zealand.”

From the semi-tropical beaches of Cape Reinga to the glaciers of Franz Josef, and from the fiords of Milford and Doubtful, over the Southern Alps, to the plains of Canterbury, New Zealand packs stunning examples of Earth's most beautiful ecosystems into a land mass the size of Colorado. Moreover, the hiking is some of the most hassle-free in the world, with no snakes, poisonous insects, large predators or even significant altitude to contend with, as the scenery at 4,000 feet rivals the Andes at 14,000. And best of all, with a full third of the country designated as National Parks and a hands-on Department of Conservation, the tracks are obsessively maintained, with backcountry huts that feel more like stripped-down inns. From north to south, four hikes provide a diverse sampling of New Zealand's ecosystems.

Blasted lands
Tongariro National Park (also known as the setting for Mordor, the fictional universe of Middle-earth in JRR Tolkien's Lord of the Rings.)
Best known tracks: Tongariro Crossing/Northern Circuit

The North Island is not known for its multitude of mountains: the area's three lone peaks - Tongariro, Ngauruhoe and Ruapehu - stand isolated, rising up from the surrounding farmland.  The trio of volcanoes were donated to the British Crown and became the country's first National Park in 1894. The Northern Circuit circumnavigates Mount Ngauruhoe, better known to the world as the Lord of the Rings' Mount Dhoom. The  four-day walk passes through old lava flows that have eroded into black-and-red sand deserts, dotted here and there with a hump of pale white moss or a spray of neon yellow wildflowers. The aridity and bareness of the place tends to leave trampers a bit shell-shocked when they pass from the edge of a desert into a dense beech forest slaked by a rushing river.

The most spectacular part of the trek is the second day, which doubles as the one-day Tongariro Crossing, the most popular one-day walk in New Zealand. Walkers climb to the base of Ngauruhoe in the morning (with many choosing to climb the absurdly steep ash cone as well), passing between Ngauruhoe and the once mighty Tongariro (now the exploded shell of a mountain more so than a real peak). But the main draw is the prism of geology on display: Red Crater, with its lip of deep purple, Emerald Lakes, with their popsicle-hued yellow and orange streams, and finally Blue Lake, the normality of its colour perhaps the most shocking of all against the unearthly surrounds.

Tropical paradise
Abel Tasman National Park
Best known track: Abel Tasman Track

In a country known for its mountains, the most popular trek is a beach walk. The Abel Tasman Coastal Track sees 30,000 visitors a year, with hikers and kayakers dipping in and out of its limestone coves and stopping to lounge on its white sand beaches. The jewel-like colour of the water as it shifts from blue to green to almost yellow invokes the North Island's volcanic region. Abel Tasman is flatter than most of New Zealand's walks, but it replaces climbs with a different obstacle: tides. Hikers have to decide if they are going to plan their whole day around low tide crossings or just walk the extra distances around the bays. Still, following the high tide crossing helps avoid the hike's other two pests: sand flies, which cannot fly as fast as people walk, and those pesky other hikers, who are probably looking for the same beachside solitude as you.

Alpine wonderland
Arthur's Pass National Park
Best known track: Avalanche Peak

About 3,000 vertical feet - that is all it takes in New Zealand to go from rolling greenery to exposed rock ridges where it is too cold and windblown for most grasses, much less trees, to grow. Due to the country's location in the Roaring Forties latitudes, 3,000 vertical feet is much more extreme than the same altitude ascent in a milder climate. The Avalanche Peak hike is perhaps the most dramatic way to experience this phenomenon, as it climbs this height, and descends it again, in a stretch of only 4.5 miles. Climbing Avalanche Peak (6,013 ft) feels like hiking out of the Grand Canyon, only the shifting strata are plants, not rock. At first the trees are big and burly, covered in a thick red moss. Then the trees begin to shrink and hunch, like old men, beards of pale green lichen hanging from their limbs. Next the trees disappear altogether, leaving only the hardy clumps of tussock grass on the hillside. Finally, these too fall aside, and it is just you and the sharp black rock as you make their way along the ridge to the summit, snow-capped peaks gathering round to welcome you into their domain.  Well, just you, the rock and those cheeky keas, New Zealand's alpine parrot. First they make you laugh, then they steal your lunch. You have been warned.

Ancient forests and deep fiords
Fiordland National Park
Best known tracks: Kepler Track, Routeburn Track, Milford Track

Although Fiordland has several celebrated walks, the Kepler Track is probably the easiest to navigate, as it begins and ends in a town, requiring no extra transport. Hikers travel from the shores of Lake Te Anau to the shores of Lake Manapouri via a full-day tramp along an exposed ridge, looking down on the park's namesake fiords. It is hard for those who regularly lust after alpine scenery to contemplate, but the last two days - flat trekking through forest - are probably the tramp's highlight.

It feels like you are walking through a painting. Fiordland's forests are predominantly made up of beech trees, whose tiny, regular leaves dot the canopy with small, delicate brushstrokes. With more than 20 feet of rain a year, these forests are as wet - and correspondingly lush - as a tropical rainforest. Ferns carpet the forest floor while moss carpets the trees; rarely is a patch of trunk visible. The path itself, tan and loamy from the millions of fallen beech leaves, feels like it is chalked in, like Dick Van Dyke's magical paths in Mary Poppins. The last night comes along the shores of Lake Manapouri, where the waters are as warm as any lake on the South Island, just begging to cool your legs.

Clarification: A previous version of this article stated that the Serengeti was in Kenya. The Serengeti region encompasses the Serengeti National Park itself, the Ngorongoro Conservation Area, Maswa Game Reserve, the Loliondo, Grumeti and Ikorongo Controlled Areas and the Maasai Mara National Reserve in Kenya.