To qualify for this challenge you have to find caches in at least 10 different countries.
10+ different cache types in one country.
9+ different cache types in a 2nd country.
8+ different cache types in a 3rd country.
7+ different cache types in a 4th country.
...
1+ cache in a 10th country.
That means you have to find a total of at least 55 caches, at least 10 different types and at least 10 different countries.
Placement is T1.5, but traveling to 10 different countries isn't easy.
This is a challenge cache
A challenge cache means that the container is at the posted coordinates, but to be able to log it as a find you have to fulfill certain requirements.