My aching legs feel heavy as lead, my hip bones sting as 15 kilos of backpack bites into skin already rubbed raw. It’s four days since my last wash and two hours since I wolfed down a bowl of porridge and cup of tea at 6am. Yet I’m smiling from ear to ear, there’s nowhere I’d rather be.

Why the masochistic happiness? Because I’m hiking in New Zealand’s Southern Alps, with no-one but my husband and birds for company as the mountains wake up, knowing there are few other ways to experience such beauty and peace.

The rewards reaped from taking up the hiking challenge in New Zealand, or tramping in the local lingo, are more than worth the pain. As national hero Sir Edmund Hillary put it,

“You don't have to be a fantastic hero to do certain things ... You can be just an ordinary chap, sufficiently motivated to reach challenging goals.”

Admittedly, our goal of a five day tramp to a maximum height of 1300m is somewhat dwarfed by conquering Everest, but it felt significant given our inexperience.

The Department of Conservation (DOC) runs a vast network of tramps across both islands. In the early 1990s, the eight most spectacular were designated Great Walks, requiring special permits. The three day Routeburn Track is the second most popular of these, attracting more than 10,000 trampers a year, and the one we decided to tackle. To extend the tramp to five days, we linked the Routeburn to the Greenstone river valley, hoping for a nice gentle end to the trip for the anticipated tired legs.

Before hitting the trail, we faced the time-consuming task of provisioning. Queenstown took the edge off this, providing a picturesque, well-stocked base for adventuring in the surrounding hills. The bustling lake-side resort town brims with outdoor shops, assistants eager to explain the latest gear and provide helpful local knowledge whilst swiping your card.

A breezy Monday morning found us winding our way around Lake Wakatipu to the trailhead, our supplies miraculously squeezed into weighty backpacks. A surreptitious survey of the other bus passengers revealed a group of varying age, nationality and style. Wiry locals in thermal leggings and baggy over-shorts sat back and relaxed, whilst backpackers in zip-off trousers and brightly patterned Europeans eagerly peered out at the sun-lit peaks revealed by lifting cloud.

At the Routeburn Shelter start point, we heaved our packs onto our backs and set off briskly. We were already far behind two fast and silent European ‘über-trekkers’, whose trail of dust hung in the air.

The leisurely four hour trip started with a gentle climb through beech forest, taking us across several fast flowing creeks to the Routeburn river valley floor. A short march on the flat warmed us up for a steep, steady climb to the Routeburn Falls hut at the tree-line at 1000m.

A popular lunch spot half-way up is a 100m-wide clearing created when the hillside slid to the valley floor after floods in 1994. The water took all the trees with it, leaving a barren tract swept clear of all vegetation as an awesome reminder of nature’s might.

Feeling proud of our first day achievement, made easy by fresh legs and enthusiasm, the view from the hut veranda was our reward. The hut overhangs a cliff, perched on stilts. It affords panoramic views of craggy, occasionally snow-scattered peaks standing guard over the green valley below.

A second reward for our early arrival was a choice of bunks for the night. The Routeburn huts are the Sheratons of the walking world. Each is spacious, clean and well-equipped with bunk bed dorms, cold water washrooms, and open dining areas warmed by a welcoming fire and lined with gas stoves and sinks.

Come 5pm, as the light outside faded to pink and purple, blue flames fiercely pummelled water billies for recovery cups of tea and early dinners. The surprisingly tasty freeze-dried meals made a good showing alongside packet soups, and dark bread, salami and cheese for the über-trekkers huddled in the corner. After a game of cards, diary entry or neighbourly chat, the common area emptied early as weary trampers took their aching limbs to bed.

The highlight of the Routeburn track is day two, spent above the tree-line between Routeburn Falls and Lake Mackenzie. Unexpected delights revealed by our early start helped me forget the recently rediscovered muscles in my legs and face stinging from an ice cold wash; frost encrusted succulents yet to feel the sun and a temporary ice sculpture formed by water droplets coating a well-placed mound of grass.

By mid-morning we arrived at Lake Harris, whose still, indigo surface perfectly reflected the surrounding peaks and clouds. Reaching Harris Saddle just above the lake, the high point of the tramp at 1277m, was an excellent excuse for a rest. However, given the unusually clear skies (the area receives annual rainfall of around 5000mm) we chose to dump our packs and scramble up Conical Hill’s steep, icy path for a one hour side trip.

The sense of weightlessness without our packs was liberating. We flew up the hill. At the top, plenty of boulders offered themselves as seats for quiet contemplation of the 360° view; the bare, jagged peaks of the Darran Mountains, the u-shaped Hollyford valley, Lake Harris below and the shimmering Tasman Sea meeting the horizon to the west.

Linking the Routeburn to the Greenstone track results in a long and tiring walk on day three. However, it affords a pleasant change in scenery from rugged alpine to softer valley, swapping an uneven rocky path for bouncy leaf mulch. The undulating track from Lake Howden hugs the wooded valley sides, crossing a small saddle before dropping down to the lakes and long grass of the flats.

The Greenstone felt more adventurous, with fewer hikers and rustic backcountry huts. Still comfortable, and a blessed relief after six hours on the move, these were older, much smaller, with outdoor toilets and no gas. Bunks can’t be booked ahead, so we were exceedingly happy to arrive at the 16 bunk McKellar Hut well before the 13 teenagers and three teachers coming the other way.

You’d think hiking for eight hours with mum’s wok and other utensils on their backs would leave the kids ready for bed, but of course, being teenagers they were just getting started. Despite the disruption we enjoyed much more interaction with our fellow trampers, perhaps due to the increased sense of adventure and lack of space.

The friendly hut warden also joined us for the evening. Each hut has a resident warden, responsible for the hut and surrounding sections of the trail. Without power for television or radio, trampers are their primary source of entertainment and human interaction. Mr McKellar Hut’s tales of running the 40km Routeburn track for fun left us in awe and not a little incomprehension.

Day four started early. The typical scene of busily roaring gas burners illuminating thermal-clad trampers hunched over mugs of tea and bowls of porridge was soon replaced with another: the “Oh my god, how is my pack heavier than yesterday?” panic. Once placated – yes we did eat food from your pack and yes it is just your gear in there – we set off into the half-light.

My cheeks were instantly chilled by the cool, damp, morning air. I took two deep breaths and marched into the woods ahead. Walking poles helped set my daily rhythm; pole pole left right, pole pole left right. Blood soon flowed to my aching legs, the light gradually sharpening the shapes around us and waking the inquisitive robins.

After less than an hour we left the lichen-covered trees and entered the open flat of the valley floor. A low mist hung heavy in the valley, still in shade and wet with dew. The silvery snake of the river slid past as we skirted its banks. Around one bend, we stopped in wonder.

A shaft of light had broken into the valley through a chink in the surrounding rock walls. Diffused by the mist, it created a mystical glow above the river, and spot lit a small, brown patch of fissured rock in the looming shadow across the valley.

And there it was, the moment that caused a smile to split my face from ear to ear. Except that the beauty of tramping in New Zealand is that these moments happen every day. Go on, challenge yourself.