Photo Essay: The Tongariro Alpine Crossing

You don't decide when you're going to climb Mt. Tongariro. The mountain decides when you're going to climb it. Even at the height of summer (that's January down under), thick clouds and rain can leave this 1,967-meter volcano inaccessible to hikers. Thus it was when we first hunkered down in one of the lodges near New Zealand's Tongariro National Park. The day of our hoped-for trek dawned dark and drizzly and there was nothing to do but move on to warmer climes.

Still, the allure of what the guidebooks all call "New Zealand's best one-day hike" lingered, and we decided to try our luck again while returning through the area the following week. This time, the sun smiled on us, and we set out early in the morning with food, water, and layers aplenty for the 18.5-kilometer Tongariro Alpine Crossing. Don't let the teenagers cavorting up the mountain fool you: This is a serious venture, and one where scorching sun can quickly turn to biting wind, especially on the exposed ridges, where hikers can be reduced to a literal crawl.

Although a hugely popular trek, the crossing's otherworldly expanses are vast enough to make each hiker feel alone with the elements and strange enough to convince each visitor that theirs are the first eyes to behold such a scene.