This is unique lava cave in north Iceland with a geothermal hot spring inside. It used to be a secret bathing spot until the water got too hot during volcanic activity in the area from 1975-1984. Even though you're not supposed to take a dip in the hot spring, you can still have a sneak peek into the cave.

Fun fact: You might recognize it from Game of Thrones, where Jon Snow and Ygritte had a steamy scene.

QUICK NOTES:

• What it is: A lava cave in North Iceland with a geothermal hot spring (not for bathing).

• Best season: Summer.

• Nice to know: Bathing is forbidden. You need to do a quick climb to get down into the cave, nothing too serious but still a little scramble.