Volcanoes, vanilla and vertical drops

Who said beach breaks have to be lazy? Verena Vogt gets active on a twin-centre holiday in Reunion and Mauritius

We’re 15 minutes into our helicopter flight when we suddenly lose speed, and the deafening sound of the rotor blades fades.

It’s a rather worrying development considering we’re flying high above a gorge with sheer vertical cliffs and no obvious place for an emergency landing.

But it seems our pilot has simply slowed down so we can get a good look at waterfalls cascading below us, and soon we’re back at full speed, zipping over mountain ridges and into lush green valleys.

I’m on Reunion, a French overseas territory in the Indian Ocean, and our half-hour flight is the perfect introduction to this mountainous island.

Often overshadowed by its beachringed neighbour, Mauritius, Reunion is an outdoor enthusiast’s dream, and combining both islands in one holiday means I get to explore two very different worlds.

With its jungle interior and volcanic peaks rising to more than 3,000 metres, Reunion is particularly popular with hikers, as many of its natural wonders can only be discovered on foot – or by air. Among them are the three cirques or calderas; tree-covered valley basins hidden deep inland that were created by collapsing volcanoes.

From the air, we spot the most remote of these, Mafate, which is dotted with tiny villages and only accessible via a two-day hike.

Our guide, Alexis, a wiry Frenchman with bags of charm, tells us that rafting and canyoning are other popular pastimes here, as is cycling – either along the 200km coastal road or, if you have the stamina, up the steep and winding roads to the island’s interior.

But I decide to skip the high-intensity exploits and instead head south-east to Grand’Anse, where a well-worn forest path leads us to clifftops and uninterrupted ocean views.

After an hour’s drive further east, we stop at the Grand Brule, a 60-metrewide hardened lava flow created by repeated outbursts of the Piton de la Fournaise, one of the world’s most active volcanoes.

The grey landscape has an otherworldly feel, and we detect few signs of life as we walk across the rough elephant skin-like surface back to our vehicle.

The eruptions that caused these flows also created lava tunnels; kilometre-long underground networks that can be explored on guided tours.

We follow a slippery path, descend into a hole no more than two metres wide and find ourselves in a basalt tunnel that stretches for 700 metres up into the mountain, and all the way down to the sea.

Equipped with headlamps, we take a few steps before we switch off the lights and find ourselves in complete darkness.

A nice moment for some quiet reflection – until we hear scuttling noises. Are we being attacked by the white crabs that live in these tunnels? No, it turns out to be our guide playing a joke.

We decide to calm our nerves with food, and as we arrive at the local market in Saint-Paul, we’re reminded that this is a slice of France in the middle of the Indian Ocean, with pain de campagne, macarons and brioche sitting alongside tropical fruit such as goyaviers (small and red with a slightly tangy taste) and combava (a wrinkled type of lime).

And everywhere we look, there is vanilla. It was on Reunion in 1841 that a young slave discovered vanilla