Hiking Iceland's Hidden Lava Tubes: A Subterranean Adventure
For travellers departing from Sydney or Melbourne, Iceland sits closer than many realise, with one-stop services via Doha or Singapore typically putting Reykjavík within 22 to 26 hours door to door. The island's reputation for glaciers, geysers and waterfalls overshadows a quieter wonder tucked beneath the surface: a network of hollow lava tubes carved by eruptions that occurred thousands of years ago. Walking through these volcanic corridors offers a different rhythm of travel, swapping wind-scoured ridges for still, dripping chambers lit by headlamp.
Australia has its own cave heritage, of course, from the limestone showpieces of Jenolan in the Blue Mountains to the dolomite halls of Mole Creek in Tasmania. Yet the comparison only goes so far. Iceland's tubes were not dissolved but born in fire, leaving behind long, arched tunnels with rope-like walls of frozen basalt. For bushwalkers used to eucalypt forests and coastal headlands, the shift in landscape feels entirely foreign.
Iceland's lava tube network at a glance
Iceland's accessible lava tubes cluster across the Reykjanes Peninsula, the Hallmundarhraun lava field in Borgarfjörður and the western edge of the Þingvellir area. Each formed when the outer crust of a flowing lava stream hardened while molten rock continued to drain away, leaving a hollow pipe. Some run several hundred metres; others stretch beyond two kilometres, with side passages and ceiling collapses that filter soft daylight from above.
| Lava Tube | Region | Length | Public Access | Notable Feature |
|---|---|---|---|---|
| Raufarhólshellir | Reykjanes Peninsula | ~1,360 m | Boardwalk tour year-round | Longest accessible tube near Reykjavík; dramatic colour shifts |
| Víðgelmir | Borgarfjörður | ~1,500 m | Guided tours (summer) | Iceland's largest cave by volume; ice formations persist into July |
| Surtshellir | Hallmundarhraun | ~1,970 m | Self-guided (with permit) | One of the world's oldest known lava tubes; historic outlaw refuge |
| Leiðarendi | Reykjanes Peninsula | ~500 m | Easy guided loop | Colourful mineral walls; good introduction for first-timers |
Choosing the right cave for your ability
Australia's bushwalking culture categorises tracks by gradient and distance, but underground environments add a layer of difficulty that comes from ceiling height, footing and total darkness. Casual visitors can manage Leiðarendi without much fuss: a short loop with reinforced paths and warm lighting, suitable for anyone comfortable on a moderate bush track back home. Raufarhólshellir is the next step up, deeper and longer but still equipped with walkways and handrails.
Víðgelmir and Surtshellir require firmer commitment. Víðgelmir is reached through a curved tunnel entrance that feels almost submarine, and the floor inside is uneven basalt broken up by long-standing ice. Surtshellir, by contrast, demands more from the traveller: sturdy boots, a reliable torch, layered clothing and a willingness to crouch through low sections. Adventurous Melburnians or Sydneysiders who have completed multi-day routes like the Overland Track in Tasmania or the Larapinta Trail in the Northern Territory will find Surtshellir within their range.
Packing for the underground
Most Australian visitors underestimate how cold Icelandic caves stay year-round, hovering between 0°C and 4°C regardless of season. Wool base layers, a windproof outer shell and a beanie make a noticeable difference, even inside a tube that looks tropical at first glance. Headlamps with a red-light mode preserve night vision and disturb the cave's quiet less, and a spare set of batteries is wise, since cold drains cells quickly.
Sturdy hiking boots with grippy soles handle the lava rubble far better than runners, and gloves help when bracing against walls during tight squeezes. Australian outdoor outfitters like Kathmandu and BCF stock most of what travellers need before flying out of Brisbane or Perth, though heavier-duty caving kit is usually rented on arrival through operators in Reykjavík.
What to expect from the sensory experience
Coming from wide brown horizons, the first few minutes underground feel oddly oceanic. Drops echo, breath fogs, and the headlamp beam grazes walls textured like petrified rope. Colours shift with mineral content: ochre streaks from iron, pale greens from algae thriving in lantern light, and the occasional glint of black glass where the original basalt chilled fast. Raufarhólshellir shows this palette dramatically, its chambers changing tone as the tour descends.
Silence is the most striking feature for many visitors from busy Australian cities. Without wind, surf or traffic, the cave carries only drips and the soft shuffle of boots. Guided groups are kept deliberately small, and in winter the larger tubes feel close to private. A growing number of photographers travelling from Sydney are timing their visits for the long polar nights, when the contrast between total above-ground darkness and the warm glow inside the lava tube creates memorable shots.
Wildlife, geological curiosities and cultural lore
Iceland has no native cave-dwelling mammals, so the fauna is largely limited to small bat species passing through Surtshellir and the occasional Arctic fox sheltering near entrances in winter. Mineralogy does the heavy lifting in terms of visual interest, particularly the lava stalactites and lava stalagmites that formed as molten drips fell from the ceiling during the original eruption.
Local folklore adds another layer. Surtshellir takes its name from Surtr, the fire giant of Norse mythology, and outlaw sagas describe bands of men hiding deep inside the tunnel during the 11th and 12th centuries. Víðgelmir's chambers have been studied by vulcanologists since the 1990s and now sit inside a protected sheep enclosure, with visitors crossing a stile before walking in. Knowing something of these stories beforehand tends to change the way people move through the spaces, slowing them into the kind of attentive wandering that bushwalkers in the Australian Alps would recognise.
Getting there, timing and responsible travel
Travellers flying from Australia usually arrive in Reykjavík via Doha, Dubai or Singapore, then hire a 4WD for the Reykjanes tubes or book a guided day trip with transport included. Self-drivers should check road conditions on the Icelandic Met Office site, which Australians in winter learn to read with the same care as a bushfire warning back home. Summer brings easier access but bigger crowds; shoulder months like May and September often reward visitors with longer daylight and far fewer tour buses.
Most lava tubes sit on private farmland, and the entrance fee paid at Víðgelmir or Raufarhólshellir supports both maintenance and conservation. Touching sensitive walls leaves oils that degrade colour over decades, and the boards inside the most-visited tubes are there for a reason. Travelling with a guide is the simplest way to keep impact low while learning the geology in detail. For those planning a wider Iceland itinerary that also folds in hot springs, the Westfjords or a soak in Mývatn's baths, this travel archive keeps track of regional highlights worth combining with a cave day. A thoughtful pace, decent boots and a healthy respect for cold and dark tend to deliver the kind of trip that lingers well past the flight home.