At the world's tallest waterfall the rock walls are sheer, the water wild and white

PJ Franz catches the spray of Angel Falls in Venezuela

The boatmen looked at the river and shook their heads dolefully. It was the tail end of the rainy season and river levels were already falling. The chances were that our expedition to Angel Falls was going to be a short, failed one.

We made camp on the river bank, slinging hammocks and lighting fires, and wondered if this was it. But that night it rained - a rhythmic lullaby on the wonky tin roof above our heads - and it was all smiles in the morning. The water was up by a good metre. We reckoned we would make it after all.

When the cloud is not too thick, it is possible to fly over the Falls, like Jimmy Angel did back in the Thirties. Well, not exactly like he did: tour operators these days prefer not to leave their clients stranded on the top. Like most people back then, Jimmy Angel was in Venezuela to look for gold. Completely broke, he had been hired one day to fly his monoplane to a table-top mountain, or tepui in the lush Gran Sabana region to the south, where there was, so he was told, lots and lots of gold. Indeed, it turned out there was so much gold he couldn't take all of it for fear of overloading the plane. But what the hell, he figured, he could always come back another time.

Angel did attempt to go back, but he could never find that particular mountain again, however much he tried. One day he saw a summit which looked promising and, ever hopeful, he landed, only to find a boggy surface which mired his plane, and a sorry lack of precious metal. But he did find a waterfall: the highest waterfall in the world. Some 15 times taller than Niagara, it would be named after him, but the story goes that he wasn't too impressed at the time. Immortality was scant consolation for an 11- day walk to the nearest village, with no gold.

His plane, El Rio Caroni, was left up there until 1970, when it was removed and put on show at the airport in Ciudad Bolivar. Small and ungainly, it sits by a low fence, a sad relic of a more daring past. It's a wonder it ever got in the air, it looks so fragile.

Our group, an assortment of Brits, Swiss and Canadians were making the journey in a large dug-out canoe, having flown down to the Lodge at Kavak, in the heart of Canaima National Park. Although it's little more than a collection of huts with strong beams and sandy floors set next to a clearing for light planes to land, Kavak is a good place to practise getting in and out of your hammock.

The local Pemon Indians, who own this land, organise trips to the Falls and look after the day-to-day running of the Lodge. It was they who took us in hand as we set off for the river, carefully stowing our gear and collecting drums of petrol.

Hats firmly on heads, we were ready. The engine kicked in with a roar. One of the boatmen sat on the bow, his feet dangling in the water, occasionally raising an arm to indicate left or right as rocks showed through the surface and the water ahead started to churn. Getting a boat through rapids can be a precarious business. Often we would stop for everyone to get out and walk through the trees on the river bank, while the boat was manhandled through the frothing water. There were a couple of sticky moments when the canoe looked out of control, but then it was through and everyone cheered.

It was on the second day that we caught our first glimpse of Angel Falls, twin plumes of water falling from the sky. The mountain, dark and tall, was shrouded in cloud. Anything could be lurking up there, and probably was.

Base camp at Angel Falls is large, with room for two or three groups. We slung our hammocks, changed into dry clothes and marvelled at the sight of the Falls over the top of the trees, the rock turning gold and red in the setting sun. A kerosene lamp and countless fireflies illuminated dinner, a mellow affair with plenty of rum.

The morning saw the last stage of our journey, the climb to the Falls themselves. It takes about an hour to climb to the mirador, the group of rocks which serves as a vantage point from which to see the Falls in their entirety, and it's tough going - steep and hot. The sun doesn't penetrate the canopy, and the dense vegetation is all roots and lianas and damp, rotting leaves. The guides sauntered ahead as if out for a stroll, while my breath sounded thunderous in my ears.

The effort was well worth it. I had heard that the Falls are so high that, during the dry season, the water is mist by the time it reaches the bottom. By the time I got there I could well believe it. The walls are sheer, the water white and wild, and only the brave swim in the pool above.

We made our escape more quickly than Jimmy Angel had managed. Two more days on the river awaited us: two more days to get to Canaima and the flight to Puerto Ordaz. Another early start, the familiar ritual of loading backpacks and life-jackets, and then the Falls were behind us. We saw them every so often, as the river twisted back and forth, until with a final turn from the boat they disappeared from view.

How to get there

British Airways and Viasa of Venezuela fly direct between Heathrow and the capital, Caracas. The lowest official fare on BA is pounds 883 return, but discounted fares are widely available. For example, Steamond (0171-730 8646) sells the same BA flight for pounds 500. An alternative is to find a cheap seat-only deal on a charter flight to Margarita Island, part of Venezuela.

How to get in

Just take a passport; British citizens do not need visas.

How to get around

Air fares within Venezuela are low. Specialist agents will be able to book seats and offer discount arrangements. Plenty of operators offer trips around the country, such as Gane & Marshall (0181-441 9592); this company offers birdwatching, trekking and a bike trip that ascends to 14,000 feet in the Andes.

How to find out more

Venezuela is on the the Internet, at a web site operated by the tour operator Last Frontiers. The address is http://ourworld.compuserve.com/homepages/lastfrontiers. The Venezuelan Consulate-General in London operates an information service, but uses a premium-rate number: 0891 171221.