Iceland's Eyjafjallajokull
Photo: Iceland's Eyjafjallajokull / iStock.com/ MLiberra

10. Going inside a volcano 

Fire and ice are the themes of this experience in Iceland. You’ll head to the glacial peak of Eyjafjallajökull to actually explore inside the active volcano. A helmet and hiking gear are provided; thermal fields, bubbling hot springs, and other extraordinary views a given.

Do It With: Royal Caribbean