5 Best Places for Adventure Travel in the World

2. Blue Mountains, Iceland

Recommended Activity: Descend into the Thrihnukagigur Volcano

Insider Monkey Score: 6.62

The Thrihnukagigur Volcano is a dormant volcano near the Blue Mountains of Iceland. The volcano has 3 peaks, the last of which erupted 4,500 years ago, leaving behind a vacant lava chamber. Since 2012, this crater has been opened to the public who can hike to the peak using a 2-mile trek before descending down into the heart of the mountain. The descent is approximately 120 meters; however, it feels very much like a journey to the center of the earth. Inside the chamber, tourists get to observe a speleological miracle as the crater expands into a vast magma chamber whose walls are lined with mesmerizing mineral deposits.