I'm a full-time travel writer and this rail trip was the best holiday of my life

The train - almost a kilometre long - is slicing its way through a flea market in Lusaka, the capital of Zambia. As it inches towards the station, a dense sea of humanity - an absolute riot of wild colours - splits to give way.

Thousands of men and women - rather nonchalantly - shift the stalls they had set up right on the track inches away from the whistling train, as groups of barefoot children, with happy stray dogs in tow, run along the moving carriages.

I'm witnessing this impromptu theatre from one of those carriages. We're arriving in Lusaka as part of Rovos Rail's epic 16-day journey from Cape Town in South Africa to Dar es Salaam in Tanzania, with three other countries - Botswana, Zimbabwe and Zambia - in between.

While the train is right on schedule, somehow the locals have missed the memo and set up the market right in its way.

The inconvenience is short-lived, though. After a brief stop, the train slowly snakes its way out of the city, and as soon as it leaves the site of the market, the entire population descends back onto the track, and the haggling and the shouting and the selling and the buying resumes as if nothing happened.

Africa is best known for wildlife safaris, but this slow, immersive rail journey - spanning five countries and 5530 kilometres, skirting along dozens of national parks, and weaving through countless tunnels, switchbacks and viaducts - is revealing vignettes of the Mother Continent most outsiders never see.

Towards the start of the trip in Pretoria, for instance, I stand next to a nine-metre-high statue of Nelson Mandela on the grounds of Union Buildings - the official seat of the South African government - and visit the Rovos Rail Station Museum, where I enjoy a buffet lunch on the platform, among free-roaming peacocks.

Towards the end of the trip, in Zambia's Northern Province, a short hike takes me to Chishimba Falls - a trio of waterfalls along the Luombe River - where through vigorous spray we watch a crystal-clear sky fill with multiple rainbows.

The piece de resistance of the trip, however, begins to unfold on day nine of the journey, when our train - with 21 carriages and just 60 guests - slowly screeches to a halt, right outside the legendary Victoria Falls Hotel near the border of Botswana and Zimbabwe.

A gorgeous tapestry of spotless white walls and crimson rugs, endless corridors and spiral staircases, tranquil courtyards and lush gardens, and enormous chandeliers in dining rooms alive with the clink of fine bone china, the Grand Old Lady of the Falls - as the hotel is often referred to - is a step back in time. Perhaps to 1947, when King George VI stayed here with his family, including a 21-year-old Princess Elizabeth, who went on to become the UK's longest-serving monarch.

But even more compelling than the hotel's design and history is its proximity to Victoria Falls. When they're in full swing (March to May), their spray is enough to water the sprawling lawns of the property.

Having arrived here in August when the falls are way more dormant, I don't feel the spray as I walk towards the edge of the hotel's gardens overlooking the breathtaking Batoka Gorge. But in its absence the view of Victoria Falls Bridge is crystal clear.

The 198-metre structure - engineered by the same man, Ralph Freeman, who designed the Sydney Harbour Bridge - is a staggering feat of architecture, connecting two nations (Botswana and Zimbabwe) above the mighty Zambezi.

Next morning, I soak up its views from a very different angle on a scenic helicopter flight. Fringed by the cascading Victoria Falls, the bridge is an absolute feast for the eyes from up in the air.

A true heart-stopping moment occurs when - from the window of my helicopter - I spot another helicopter hovering, in Top Gun style, between me and the bridge.

Later that day, I get one more hit of the monumental structure. Minutes after departing Victoria Falls Hotel, the train slowly saunters over the bridge connecting the two countries, eventually coming to a complete stop, and allowing guests to walk on the bridge and then to a lookout, where they can get themselves snapped against the backdrop of the bridge, just in time for sunset.

While much of the 16-day rail journey winds its way through parts of the continent rarely seen by visitors, it makes sure guests get their hit of the African savanna and its wildlife.

A two-night stop at Tau Game Lodge in South Africa's Madikwe Game Reserve, with wildlife drives every morning and evening, is the first major off-train excursion on the itinerary.

Within minutes of arriving at the lodge, I strike gold. My standalone villa is perched on the edge of a rivulet, and as soon as I walk onto my outdoor deck, I spot two lionesses and a cute cub quenching their thirst.

There are dainty gazelles, too, maintaining a safe distance from the apex predators. And elephants, with little ones in tow, throwing dust on themselves - a natural sunscreen. And boisterous monkeys - dozens of them - creating a ruckus from high up in the branches.

But it is on the game drive later that evening when a rare performance unfolds metres away from my open jeep.

As my guide, Herman, winds the vehicle through spiky sickle-bush, parched acacias and bone-dry grass shimmering in the golden late-afternoon sun, we spot the indisputable stars of the 75,000-hectare reserve: a strapping full-maned lion and a beautiful lioness laying in the grass on their backs - their paws up in the air.

So still and stiff are they, I at first think they're carcasses - until Herman clarifies they're just "taking a break".

The lioness, you see, is on heat and for three days the couple will mate every 15 minutes or so. "The lion won't leave her side - they won't eat, they won't drink. They'll just mate," Herman says.

And within minutes, they're at it, in full view of the three safari jeeps with snap-happy travellers from all over the world.

The show lasts for just 10-15 seconds before the couple collapse again on the grass - their paws up in the air, as if nothing happened, completely indifferent to the spectators around.

Old jeeps leave and new jeeps arrive. "Only three vehicles are allowed to hang around the wildlife," Herman clarifies. "We don't want to overwhelm them with our presence." And the show continues - every 15 minutes or so.

I'm a full-time travel writer and people often ask me about the best holiday of my life, and I tend to um and er because I can't decide. But this trip has everything - adventure, luxury, wildlife, food and drink (more on that below), and a real sense of journey - and I have to say, this one takes my top spot.

It's day 12 of the journey. After traversing the rugged landscapes of South Africa, Botswana and Zimbabwe, the train is now rattling its way through Zambia, where the earth is all but flat, except for the majestic baobabs seemingly guarding the timeless terrain.

I wake up in my Deluxe Suite - with gorgeous mahogany wall panels, a double bed next to big picture windows, a small dining area and an ensuite.

I have a cup of coffee, sift through a few pages of my book (Half of a Yellow Sun by Chimamanda Ngozi Adichie), fill my eyes with the sight of the baobabs drifting past and then go back to sleep.

When I wake up again, I have a moment of reckoning.

I have been reading about slow, immersive travel for years, but this is the first time I am truly experiencing it.

The 16-day itinerary is long enough for me to finally stop obsessing about taking pictures.

It's slow enough for me to stop worrying about missing the sights. (The rail tracks in this part of the continent are so old we're travelling at about 15 kilometres an hour.)

And it's disconnected enough for me to stop reaching out for my "black mirror". (We have been without phone network and Wi-Fi for a couple of days and god knows I wouldn't have gone back to sleep had I had access to Instagram.)

It's a forced digital detox, and while it made me anxious at first, I'm finally beginning to truly switch off for the first time in a very long time.

Making the task easier is the fact that today, just like yesterday, is a "train day", much like an "at sea" day on a cruise. There are many blockbuster moments on this journey - like the mating lions of Madikwe - but there are also long stretches where nothing happens, and time seems to slow down.

I make the most of these slo-mo moments in the two dining carriages that bring to life the opulence of the 1930s Edwardian era. Here, among glossy wooden panels, gooseneck lamps and thick drapes, lavish breakfasts are served (spring onion scones, anyone?) and every lunch and dinner is a four-course affair.

Forget farm to fork and paddock to plate, the cuisine on board the train is a masterclass in savannah to spoon, with courses ranging from roast ostrich in port jus to a carpaccio of kudu - a spiral-horned African antelope.

During my journey I taste dishes I have never had in my life - and most likely will never again. A highlight is bobotie - a traditional South African baked dish of spiced mince and egg - which turns up on the menu twice: once accompanied with rice and sambal; and once packed inside a warm, crisp samosa.

On my way to the dining cars I often peek inside the kitchen and wonder how the chef and his always-smiling staff manage to create such impeccable meals in a minuscule space, as well as cater to all sorts of dietary requirements.

The icing on the cake is the drinks list. Before boarding the train I spent a few days in Cape Town, from where I really wanted to do a day trip to Stellenbosch - South Africa's best-known wine region - but couldn't as I ran out of time.

I shouldn't have worried though. The train's exhaustive wine list is a roll call of Stellenbosch's top stars - from a crisp dry riesling paired with grilled salmon fillet one day to a deep merlot matched with duck confit one evening.

Between meals, and particularly on train days, I retire to the Lounge Car, where the resident historian delivers lectures on the parts of Africa we're travelling through, amid lavish afternoon teas (you really need a second stomach on this trip).

But my favourite spot is the Observation Car, right at the very end of the train, where you can grab a drink at the bar, then make your way to the outdoor deck. The African sunset is like The Lion King coming to life right in front of your eyes - an enormous yellow lozenge slowly sinking behind a wide brown dry horizon. But to witness it from the tail end of a moving train is something else. I watch the spectacle on every single day of this rail journey from this very spot - and it never gets old.

The writer travelled with the assistance of Rovos Rail