Find a cache, any cache type that already has 100, and in the event this cache ever gets 100 finds, logging this cache doesn't count as a cache with 100 finds.
The rules:
1) The cache must already have 100 or more finds on the date you find it.
2) Any type of cache may be used to qualify for the challenge.
3) You must list the qualifying cache in your online log similar to this:
GC4F0F INDEPENDENCE DAY found 4/10/09.