Victoria Falls straddles the border between Zambia and Zimbabwe.

The international setting is part of the physical geography: the Zambezi forms the border here. The waterfall is therefore a transboundary river feature, not two unrelated waterfalls on opposite sides of a national boundary.

Its main front is approximately 1.7 kilometers wide. That describes the span of the falling edge, not the width of every downstream gorge or the amount of water crossing the edge during every season.

The falls expose a dramatic change in river form. A broad upstream channel gives way to a confined gorge, concentrating the sound, spray and turbulent water within a much narrower rocky passage.

Mosi-oa-Tunya, commonly translated as the smoke that thunders, is a local name that describes the experience of the falls rather than a measurement. Water striking the gorge throws spray into the air, producing a mist plume that can be visible from a considerable distance. UNESCO describes mist visible more than 20 kilometers away, although actual visibility depends on flow and weather.

The geological setting is basalt, a volcanic rock cut by fractures. Over time, river erosion has exploited weaknesses in the rock and helped develop a sequence of gorges. The present waterfall edge is therefore one stage in an evolving landscape. The downstream zigzag of narrow passages records a longer history than the current curtain of falling water alone.

The cliff is not equally high everywhere, and islands interrupt parts of the falling edge. Water also does not arrive at a constant rate. Seasonal changes in the Zambezi catchment alter how much of the front carries a continuous curtain and how much rock remains exposed. A photograph taken during high flow can look very different from one made during a low-water period.

Width measurements need comparable definitions. UNESCO's introductory description refers to a river more than two kilometers wide at this location, while the familiar waterfall-front measurement is around 1.7 kilometers. These are not necessarily contradictory claims: the upstream channel and the actual falling edge are different features. Neither number should be substituted for a vertical height measurement.

UNESCO inscribed Mosi-oa-Tunya / Victoria Falls on the World Heritage List in 1989. The designation recognizes a shared natural property rather than assigning the spectacle to one country. Protection involves the waterfall and its surrounding river landscape, including features that explain how the falls developed and the habitats influenced by spray and river flow.

For visitors, country and season affect the view, but they do not change the underlying identity of the site. Zambia and Zimbabwe offer different perspectives on the same river system. The most useful geographical description combines the border location, the broad fall line and the narrow basalt gorge, rather than relying on an undefined claim that it is simply the world's biggest waterfall.

Victoria Falls belongs to a shared river landscape rather than a single-country spectacle. The Zambezi forms the boundary here, and viewpoints on the two sides reveal different parts of the falls and gorge. A photograph from one bank is therefore a perspective on a transboundary feature, not evidence that the entire waterfall belongs only to the country from which it was photographed.