Chasing the rare 'lunar rainbow' at Victoria Falls

A "moonbow" is one of nature's rarest sights – and Victoria Falls is one of the few places on Earth where travellers might catch it.

The first thing I noticed was not the darkness, but the sound. 

It began as a low, distant rumble, easy to mistake for wind. But as the path narrowed and the trees thinned, the noise deepened into something more primal, swelling into a relentless roar that pressed against my chest. By the time I reached the edge of the waterfall, the sound was no longer just something I heard but something I felt, pounding through me like the blood through my veins.

There were no floodlights. Only the pale wash of a rising full Moon and the thick blue-black ink of the Zambian night. Beyond the darkness, water plunged more than 100m (328ft) into the gorge below, sending vast columns of spray high into the air.

Then slowly, almost imperceptibly, the reason we had come began to take shape: a pale smudge in the spray, easy to miss unless you were looking directly at it. Then a curve emerged: a soft, luminous band stretching across the darkness, suspended above the gaping gorge below.

This was the "moonbow" – a lunar rainbow formed not by sunlight, but by moonlight.

Straddling the border between Zimbabwe and Zambia, Victoria Falls – known locally as Mosi-oa-Tunya or "The Smoke That Thunders" – is one of the world's great waterfalls. Around one million people visit each year, most of them in daylight. But after dark, during the full Moon period, the experience changes completely.  

I had not planned to be there at night. Just hours earlier, I had crossed into Zambia after a long, confusing border process from Botswana, exhausted from more than five weeks driving solo across parts of southern Africa. By the time I reached Livingstone, the only thing I knew for certain was that I wanted to see the falls.

Being there for the moonbow felt like a lucky accident. When I arrived at the park entrance about noon, a parking attendant asked if I wanted him to hold my parking spot until later that night. When I asked why, he explained that the full Moon was rising – and this was one of the rare nights when the falls might reveal their nocturnal rainbow. 

So I bought two tickets – one for daylight and one for after dark.

That afternoon, I crossed Knife-Edge Bridge, a narrow 40m- (131ft) long span running parallel to one section of the cascade, and was drenched within seconds. The air itself seemed to turn to water, every gust of wind carrying a fresh barrage of heavy droplets that soaked through my clothes and skin. At each viewpoint, the falls revealed themselves in fragments – a vast curtain of white mist here, a churning void there – until finally, at the edge of the trail, the full scale came into view: a near-continuous curtain of water stretching across the horizon.

After an hour of watching in silent awe, I made my way back to town, where I set up my tent and stocked up on some much-needed........

© BBC