Canaima National Park

Listen first. Beneath the voices and the hum of a small plane fading into the distance, there is a steady roar. It never stops. It comes from water pouring over rock into a lagoon the colour of strong tea. Feel the sand under your feet, pale and soft, and look at the water lapping against it. Close to shore it glows amber, almost pink. Further out, it turns the colour of dark honey.

You are standing in Canaima National Park, in Bolívar State, in the far southeast of Venezuela. This is one of the largest national parks on Earth. Venezuela created it in 1962 and expanded it greatly in 1975, to roughly 30,000 square kilometres. That is about the size of Belgium. In 1994, UNESCO named it a World Heritage Site. It was recognised for its landscape, and above all for its strange mountains.

Those mountains are called tepuis. Lift your eyes to the horizon and you may see one. It looks like a giant stone table, with sheer cliffs and a flat top lost in cloud. The word tepui comes from the language of the Pemon, the Indigenous people of this region. It is usually translated as "house of the gods." The Pemon have lived among these mountains for many generations. Many of the guides, boat drivers and cooks you meet here are Pemon.

Now for the first surprise. The rock in those cliffs is sandstone, and it is very old — around two billion years old. Geologists count it among the oldest exposed rock formations on the planet. The sand was laid down long before dinosaurs, long before plants grew on land. Over immense stretches of time, rain and rivers wore away the softer ground around them. The tepuis are what remained — islands of ancient stone left standing above the forest.

Because their summits are so isolated, the tops of the tepuis work like separate worlds. Plants and animals there developed apart from the lowlands below. Botanists have found many species that grow nowhere else. Some are carnivorous plants, like pitcher plants that trap insects in cups of rainwater. On a few summits there are tiny black toads that cannot jump well. When threatened, they curl into a ball and roll away. Very few visitors ever reach these summits, but the life up there shapes the story of the whole park.

That brings us to the water around you. Why is it this colour? The answer is tannins. These are natural compounds that leach out of leaves, roots and peat as rain soaks through the forest and the savanna. They stain the rivers the colour of tea. The water is not dirty. Scoop a little into your hand and it looks clear and golden. Under the falls, the churning foam turns a creamy yellow, like the head on a glass of beer.

The falls in front of you are on the Carrao River, and they spill into Canaima Lagoon. There are several of them, side by side, known by names such as Hacha, Ucaima, Golondrina and Wadaima. Together they form a wide, curving wall of white water. Palm trees lean over the beach. Behind it all rise the dark shapes of the tepuis. This view is the first thing most visitors see, because the small village of Canaima sits right on the lagoon.

Here is the second surprise. There is no road to Canaima. Nearly everyone arrives the way you probably did — by light aircraft, landing on a small airstrip near the village. From here, travel goes by river in long wooden boats called curiaras, or on foot. The isolation is part of what has protected this land. It also means that every bag of rice and every bottle of fuel in the village has come in by air or by water.

One popular walk takes visitors to Sapo Falls, close to the lagoon. A path leads behind the falling water itself. You walk along a ledge of rock with the curtain of water thundering just beside you. The spray soaks everything. The noise fills your chest. It is a good place to understand how much power these rivers carry, especially in the rainy season, when the falls swell and the air turns to mist.

And then there is the most famous waterfall of all. Deep in the park, it drops from the edge of a vast tepui called Auyán-tepui. In English it is known as Angel Falls. In Pemon it is called Kerepakupai Merú, often translated as "waterfall of the deepest place." It is the tallest uninterrupted waterfall in the world. Its main drop is roughly 800 metres. The water falls so far that much of it turns to mist before it reaches the bottom.

The English name comes from an American aviator called Jimmie Angel. In the 1930s he flew over the region, and in 1937 he landed his small plane on top of Auyán-tepui. The ground was boggy, and the wheels sank. The plane could not take off again. Angel, his wife and two companions walked down off the mountain, a journey that took them about eleven days. His plane stayed on the summit for decades. It was later removed, restored, and put on display in Ciudad Bolívar.

Writers have long been drawn to this landscape too. It is often said that the tepuis, and especially Mount Roraima on the park's eastern edge, helped inspire Arthur Conan Doyle's novel The Lost World. In that 1912 story, explorers find dinosaurs living on an isolated plateau in South America. No dinosaurs live here, of course. But standing beneath these cliffs, with cloud hiding their tops, it is easy to see why the idea felt believable.

Before you move on, take one more moment at the water's edge. Watch the foam drift slowly across the amber lagoon. Notice how the roar of the falls rises and fades as the wind shifts. Look up at the long flat line of a tepui, rock older than almost anything else you will ever touch. As you walk away along the sand, listen. That sound will follow you for a long time — the sound of very old water, falling from very old stone.