We hear her first, a low rumble, like a lion roaring out a greeting, then, great spumes of mist rising in the distance.

Earlier that morning we had crossed into Zambia from Zimbabwe, our third border crossing in less than two weeks after a whirlwind tour of South Africa, to see Mosi-oa-Tunya, The Smoke that Thunders or Victoria Falls. It is an oppressively hot day, more than 41 degrees under the shade of the fruit laden mango trees. Monkeys swing from branches above us as our guide gives us a brief safety talk about our expedition to the Devil’s Pool, a small natural infinity pool at the edge of Victoria Falls.

"We will have to swim part of the way. Can you swim?" he asks, finally.

Everyone says yes except for me, because I cannot swim. But, going to the Devil’s Pool has been on my bucket list for so long that I’m not going to let that simple fact stop me. I mumble something and look away as husband looks distinctly worried.

Our motorboat, twists and winds its way across the great Zambezi river, narrowly missing sharp, rocky outcrops, to Livingstone Island. It is here that David Livingstone first saw the Falls in 1855, and was stunned into saying, "…so lovely, it must have been gazed upon by angels in their flight." Then, according to legend, he proceeded to measure the depth of the Falls by lowering a length of calico cloth with a bullet attached to give it weight.

On the island, we are handed glasses of Maheu, a bland energy drink made out of maize and sorghum, to buck up our courage, then shown to the "loo with a view" to change into our swimsuits. My heart beats faster with fear or excitement, it is hard to say which, as we catch our first sight of the Falls.

As it is the dry season, instead of one continuous body of water, which is what we were expecting, Vic Falls is split into separate glittering ribbons of waterfall. Even then, standing at the cliff edge, we can feel the thrum of her restrained power through our feet, her untamed wildness as she crashes and plummets into the ravine, 107 metres below us.

Suddenly, the reality of what we are about to do hits us. Though there have never been any deaths here, yet it is hard to forget that we are only a few metres from the edge of the highest waterfall in the world. Are we horrible parents to have brought our boys, who are the only kids in our group? There is still time to change our minds, but we keep going. The boys and husband wade into the river, holding hands to form a human chain in the shallow parts, before letting go to start swimming slightly upstream, against the current. I hear my eldest mutter as he slips into the water, "Can’t believe you’re making us do this."

Then it is my turn. Luckily a kind guide realises that despite my enthusiasm, I really cannot swim, so he helps me across. He keeps looking around, checking the horizon, then says, in a matter of fact voice, "I need to keep an eye out for hippos or crocodiles."

"Errr… what?" I say, then jump and squeal when I feel something bite my toe.

"Oh, that’s only fish nibbling at your toes," he laughs.

Which is all the incentive I need to move quickly through the river.

The boys sit quietly, faces pale and terrified, as we wait our turn to go into the Pool. The guide, who is scrambling along the rocky ledge at the edge of the Falls like an overexcited goat, waves at us and we slip into the cool waters of the Devil’s Pool. A short swim and we are sitting, feeling slightly dazed, then lying down on the ledge to look over the abyss as a guide holds on to our legs.

The view from here is panoramic, spectacular, scary -- for the smallest mistake could plunge us over the edge, yet it is wildly exhilarating at the same time. Torrents of water wash over us, its force pushing us up and above the rim so we are glad that the guide holds on to us. Far below a rainbow sparkles in the sunlight, a bright bridge spanning the width of the canyon.

Buzzing with adrenaline, we cross back into Zimbabwe, dropping the kids off at our hotel, the beautifully colonial Victoria Falls Hotel, redolent of the British Empire with its uniformed staff and mosquito netted beds.

Before we can change our minds, the husband and I head out again, this time to zip line, tandem, over the Victoria Falls gorge. Walking to the wooden platform at the top of the ridge, where a 425metre long cable is suspended 120metres above the Zambezi at an extreme angle, has got to be one of the hardest things I’ve done. We step into our harnesses, which are attached to a pulley as we walk and then sit on the edge of the platform, our feet dangling over a very, very long drop.

This time it’s me that is mumbling, "I can’t believe you’re making me do this," to my husband.

My skin breaks out in goosebumps as we step off the platform and for a few seconds we hang there, suspended in what is nothing more than a glorified swing. The river is so very far below us. I can feel the icy tentacles of terror turn my feet into blocks of ice. I close my eyes as we step off the edge, hurtling down, down, down, the basalt face of the opposite cliff speeding towards us. But then I open my eyes and my scream of terror turns into a howl of pure, adrenaline fuelled joy as I realise that this is the closest I’ll ever get to flying.