Get your passport ready, you are going to travel. The challenge is to find a cache in 10 different countries. Not challenging enough? Try to do it within one year as a bonus. I did. But you don't have to. Some people did it in just one day! There is no time limit to complete this challenge. You may find any cache type you like (except location less) at any time during your lifetime. After you complete this challenge you may log your find and claim the World Class Cacher title. In your log please write down a list of country names and cache codes and mention how you liked your visit and caching there. Don't forget to post some nice photos :)
Is ten too many for you? You may attempt to claim the World Class Cacher Apprentice title by finding a cache in just five different countries, you may log your find, but you must state you are claiming the Apprentice title. Eight countries will grant you the World Class Cacher Journeyman title. Again you must state you are claiming the Journeyman title. When you level up you can update your log.
This cache is a great place to trade your foreign coins, souvenirs, hotel room keys, shells... Cache is not winter friendly, but why would you cache in a winter if you can cache in the Caribbean, right?
Can't decide where to go? Here is some inspiration for you.
Grand Cayman, Cayman Islands
Volcano, St. Lucia
Coco Cay, Bahamas
Campobello Island, Canada
Praha, Czech Republic
I don't remember where, I was drunk :)