Mount Elgon National Park

Listen first. Before the history, before the volcano, there is the sound of this forest. Water drips from moss onto broad leaves. Somewhere above, branches creak as a colobus monkey shifts its weight. The air is cool and damp, and it smells of wet bark and red earth. Underfoot, the soil gives a little with every step. You are standing on the flank of one of the great mountains of East Africa, and it rises so gradually that you may not feel the climb at all.

Welcome to Mount Elgon National Park. This is the Kenyan side of a vast mountain that straddles the border with Uganda. Elgon is an extinct volcano, and a very old one. It is often described as among the oldest volcanoes in the region, far older than Kilimanjaro or Mount Kenya. Over millions of years, wind and rain have softened its shape. What remains is a huge, broad dome, wider than it is dramatic, with a sunken crater at its summit.

That crater is called a caldera. A caldera forms when the top of a volcano collapses into its own emptied magma chamber. Elgon's caldera is one of the largest intact examples in the world. Inside it, the land is a bowl of high moorland, streams and grassy hollows. Around its rim stand a ring of peaks. On the Kenyan side, the highest is Koitobos, a flat-topped column of rock. Climbers often describe it as looking like a giant table set on the mountain.

Now, here is the detail that brings most visitors to this park. Elgon is honeycombed with caves. Some were carved by water, some formed in old volcanic ash. The best known is Kitum Cave. For generations, elephants have walked into its darkness at night. They are not looking for shelter. They come for salt. The cave walls hold mineral deposits, and the elephants scrape them loose with their tusks, then chew the crumbled rock.

Think about what that means. Elephants are, quite literally, mining this mountain. Over a very long time, their tusks have helped to widen the cave. Scientists who study Kitum have suggested that elephants may have played a real part in shaping it. Inside, look at the walls by torchlight. You can see grooves and scratches in the rock. Those marks were made by tusks, not tools. Calves learn the route by following their mothers through the dark.

The caves hold other residents too. Thousands of bats roost in the ceilings, and the air near the entrance can carry their sharp, musty smell. Kitum also has a more serious place in medical history. In the 1980s, it was linked to cases of Marburg virus, a rare and dangerous illness related to Ebola. Researchers later studied the cave and its bats closely. Today, visitors usually stay near the entrance areas, and rangers will advise you on where it is sensible to go.

Other caves lie close by, including Makingeny and Chepnyalil. Makingeny is known for a curtain of water that falls across its mouth. In the wet season, you can hear it before you see it — a steady roar through the trees. Standing behind falling water, looking out at green forest, is one of the quieter pleasures of this park. Each cave feels different, in its light, its sound and its smell.

As you move higher, the mountain changes around you. The lower slopes are thick montane forest, with tall trees, hanging lichens and ferns. Then comes a belt of bamboo, dense and pale green, which knocks and rattles in the wind. Above that, the trees thin out. You reach heath and then open moorland. Here grow some of the strangest plants in Africa — giant groundsels and giant lobelias, which look like something from another planet.

These giant plants have adapted to a hard life. Days at altitude can be bright and warm, while nights can drop close to freezing. The groundsels keep their dead leaves wrapped around their trunks, like a thick coat. The lobelias rise as tall, furry spikes. Both are found on only a handful of high East African mountains. Each mountain is like an island in the sky, and its plants have developed in their own way.

The animals here are often heard before they are seen. Black-and-white colobus monkeys leap between branches, their long white tails trailing behind them. Blue monkeys feed quietly in the canopy. Buffalo graze in forest clearings, and bushbuck move through the shadows. Birdwatchers come for the forest birds, and for raptors such as eagles that ride the air above the cliffs. With patience, and a little luck, you may even see the elephants themselves.

This park is also unusual for another reason. In many Kenyan parks, visitors must stay inside vehicles. Here, walking is part of the experience. With a ranger or guide, you can follow forest trails, visit the caves on foot, and climb towards the caldera. A popular short outing is the walk up to Endebess Bluff. From the top of this rocky outcrop, the view opens across the farmland of Trans-Nzoia, towards the town of Kitale.

The mountain matters deeply to the people around it. Communities such as the Sabaot have lived on these slopes for generations, and the Ogiek, a forest people, have long ties to the woodland. Below the park, the volcanic soil is rich, and the farms are green with maize and other crops. Streams that begin on Elgon feed rivers across the region. In a very real way, this mountain waters the land you drove through to get here.

Before you leave, take one more moment to stand still. Look at the colour of the soil on your boots — that deep red comes from ancient volcanic rock. Listen again for the drip of water and the creak of branches. Somewhere in the forest, an elephant may be resting, waiting for dusk and its slow walk back into the dark of the caves. The mountain is quiet, patient and very old. As you walk away, notice how gently the land slopes down behind you.