As adventure activities go, baking bread probably doesn't rank very highly in most countries. But then Iceland isn't most countries. We're at the Bjarnarflag bakery in the northernmost reaches of the island, a handful of miles from the Arctic Circle. It's midsummer and horizontal sleet steams as it hits the mud around our feet, underneath which sits the "bakery" - half a dozen pits dug into boiling soil, covered with dustbin lids, containing hverabraud - steam bread made with rye and molasses. Bending to peek inside, we're blasted with a vapour so sulphuric that you have to wonder if perhaps "Bjarnarflag" is Icelandic for "Beelzebub" and we have, in fact, interrupted a satanic scone-baking session.

As adventure activities go, baking bread probably doesn't rank very highly in most countries. But then Iceland isn't most countries. We're at the Bjarnarflag bakery in the northernmost reaches of the island, a handful of miles from the Arctic Circle. It's midsummer and horizontal sleet steams as it hits the mud around our feet, underneath which sits the "bakery" - half a dozen pits dug into boiling soil, covered with dustbin lids, containing hverabraud - steam bread made with rye and molasses. Bending to peek inside, we're blasted with a vapour so sulphuric that you have to wonder if perhaps "Bjarnarflag" is Icelandic for "Beelzebub" and we have, in fact, interrupted a satanic scone-baking session.

There's an urgency about being in Iceland. Everything from breathing to baking, walking to sleeping involves an awareness that, somehow, at any given moment, life as you know it might just cease. Straddling the Eurasian and American continental tectonic plates, Iceland is a country being torn down the middle. The ground, a lunar landscape of coal-black lava fields and ash deserts, screams from volcanic vents. The country is almost entirely devoid of trees and shrubs and, for the most part, is uninhabitable. You don't have to "do" anything to feel adventurous. Simply "being" here feels something of an adrenalin sport.

A short ride from the bakery lies Namafjall Hverir, a scorching geothermal area favoured by those after a gentle trek, a vicious landscape of belching blue-grey mud pots and smoking fumeroles. With the ground reaching temperatures of 200C, it's essential that you don't stray from the marked path. Every year a clueless wanderer or two find themselves sinking into the scorching mud. So, keeping to the marked trails we walk beneath blond sandy hills streaked with yellow sulphur deposits once mined and exported for gunpowder, and grey gypsum deposits still mined for making face creams. Every few yards, giant anthill-like steam vents send bursts of sulphuric gas into the sky. A handful of tourists wanders tentatively in single file ahead of us. Obscured by steam clouds, they seem to have been transported to different point in time - primordial or apocalyptic.

Iceland may look ancient but in world terms it's a mere teenager, exhibiting the kind of geological tantrums befitting a place that is still forming under your feet. The youngest country in Europe, it's also home to one third of the globe's volcanic activity with an eruption about once every five years. A notable explosion as recent as the 1960s gave birth to the island of Surtsey, pyroclastic spitting distance from the capital. But it is up here on Iceland's sparsely inhabited northern coast that visitors can best appreciate the island's brooding, geological weirdness. Surrounded by fields of crumbling lava tors, thermal caves and charging waterfalls, Lake Myvatan is the favoured base for a tour of Iceland's north. It is also its premier bird-watching destination, a 36 sq km expanse of spring-fed waters with tiny inlets and mossy green islands. The setting is serenely spectacular - more reminiscent of The Lord of the Rings' Hobbit Shire than the most recent Bond movie, which was filmed nearby.

Along with 007 film crews, Myvatan has recently added Paul McCartney and Prince Charles to its celebrity guest list. Both travel here regularly to fish the lakes' salmon-rich inlets. You pass a jaw-dropping mess of geology that makes you want to reach for your school science book. And things get no less spectacular as we take an afternoon flight in a tiny 10-seater aeroplane over Dettifoss, Europe's most powerful waterfall. Serious trekkers can make a two- or three-day hike through the remote Jokulsargljufur National Park to reach the falls. We are more than content to raise the heart rate with a swooping fly-by over deep lava ridges before alighting to spend the next few hours trekking around a vast lava field, at the foot of the mighty Krafla volcano. Created just 19 years ago the contorted black ground remains soft underfoot and hot to the touch, interspersed with blond sulphur sands and ice blue (but red hot) geothermal pools. No birds, no plants (save one singular, stoic buttercup), just utter, steaming silence.

The same can't be said for "night time" in Iceland. Night, such as it is in midsummer, lasts all of about an hour before dawn is breaking again. You may try to sleep behind the efficient rubber blackout curtains that line hotel windows, but locals won't. Street football is apparently a popular way to while away the sunny small hours. As, it seems, is cruising in your souped-up Ford Cabriolet.

We escape by taking a night whale-watching excursion from Husavik. One of Europe's top spots for sightings of minke whale, the sea near the town also gets more than its fair share of dolphins, humpback whale and even blue, killer and sperm whales. Donning fetching midnight-sun-orange cagoules, we take a three-hour tour out into the Atlantic, and are rewarded within minutes with a pair of minkes rolling obligingly around in front of our lurching fishing boat.

As ever it's hard to know where to look: the sea is carpeted with puffins doing their comedy clockwork-toy attempt at flying, while the sun starts to make its teasing descent towards the horizon.

Arctic Experience (01737 218801; www.arctic-experience.co.uk) offers various tailor-made and package tours of Iceland, including 'Whales, Fire & Ice', a three- or five-night break from May to September, exploring the north of the country. The price is from £726 per person, based on two sharing, including return flights from Heathrow or Glasgow, domestic flights, transfers, taxes, three nights' b&b, two whale-watching trips and tours of the Lake Myvatan area along with the services of a guide. For further information contact the Iceland Tourist Board (020-8391 4888; www.icetourist.is).

Top Ten Outdoor pursuits

1 Climb the lost Himalayas

Reach for the sky on Kangchenjunga, the world's third-largest mountain, on the India-Nepal border. The Sikkim approach has recently been reopened after 50 years. Contact World Expeditions (020-8870 2600; www.worldexpeditions.com).

2 Caribbean to Amazon Basin

Go jungle trekking in St Lucia, then sail across to Guyana to a rainforest resort on the Essequibo River with a new itinerary from Wilderness Explorers (020-8417 1585; www.wilderness-explorers.com).

3 European weekend adventure breaks

Go wildlife-watching in Spain's Parque Nacional de Donan or bear-spotting in Finland on new three-night "Natural World" breaks from Inntravel (01653 617906; www.inntravel.co.uk).

4 Gorillas in Rwanda

Home to a quarter of Africa's primates, this is the world's top spot for gorilla tracking. Take a tailor-made tour with Reef and Rainforest Tours (01803 866965; www.reefandrainforest.co.uk).

5 Marine conservation in the Azores

Study sperm whales, dolphins and loggerhead turtles, aiding an international monitoring databases as you go, as part of a new expedition from Biosphere Expeditions (01502 583085; www.biosphere-expeditions.com).

6 Ride across the Andes

Cross the Andes on horseback, from Argentinian Patagonia to the forested slopes of Chilean Patagonia, on a new programme from riding specialists In the Saddle (01299 272997; www.inthesaddle.com).

7 Sea kayaking in Antarctica

Paddle through a sea of ice floes in a kayak and go scuba diving to see penguins underwater. Contact Exsus Travel (020-7292 5050; www.exsus.com).

8 Cycle the Rockies

Mountain bike along the rim of the Grand Canyon and navigate a two-wheel path through the Rockies on a new holiday from TrekAmerica (0870 444 8735; www.trekamerica.com).

9 Shark diving in Sudan

This area of pristine dive sites, where there's a good chance of seeing sharks, is a new addition to the programme for scuba specialists Dive Worldwide (01794 389372; www.diveworldwide.com).

10 Siberian wilderness trek

Take a guided trek in the Altai Mountains, aka "Russian Switzerland", with Walks Worldwide (01524 242000; www.walksworldwide.com).