Descend 120 meters into Þríhnúkagígur’s colorful magma chamber after a 3 km hike across otherworldly lava fields. This guided small-group tour from Reykjavík pairs geology, safety-led exploration and striking volcanic scenery.
More ways to explore the area's outdoor wonders
The ground crunches beneath your boots, black glassy shards of ancient lava catching the low light as the Blue Mountains push the sky into a clean, cold blue.
Difficulty
moderate
Duration
5–6 hours
Fitness Level
Participants should be in moderate physical shape—able to hike ~3 km over uneven terrain and manage short stair/lift descent.
Wildlife
History
Þríhnúkagígur’s chamber remained intact after an ancient eruption emptied the magma, and its accessible interior was developed in recent years for guided descent—offering a rare look at a volcanic void.
Conservation
Group sizes are limited and guided routes are enforced to protect fragile geological features; stick to paths, pack out waste and follow guide instructions to minimize impact.
Reserve your spot on the Inside the Volcano: Small-Group Tour and Lava Field Hike today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Dress in layers and waterproofs
Weather on Bláfjöll changes rapidly—bring an insulated layer and waterproof shell to stay warm and dry.
Wear sturdy hiking boots
The 3 km lava-field approach is uneven and can be slippery; ankle-supporting boots improve traction and comfort.
Bring water and light snacks
The tour lasts 5–6 hours including transit—carry at least 1–1.5 L of water and energy food to maintain stamina.
Be honest about fitness and health
Not recommended for pregnant travelers or those with significant heart or spinal issues—moderate fitness is required for the descent and hike.
Waterproof shell jacket
Protects against wind and rain common on Bláfjöll and inside the crater opening.
Sturdy hiking boots (ankle support)
Provides traction and ankle support across jagged lava rock and uneven ground.
Insulating mid-layer (fleece/down)
Keeps you warm during the exposed hike and while stationary at the crater edge or in the cool interior.
Daypack with 1–1.5 L water and snacks
Carry hydration, snacks, camera, and rain cover for a comfortable 5–6 hour outing.