In which year was this cache published?
The answer : 2004
The Geocaching Headquarters geocache (GCK25B) is one of the three stops of the Trifecta, the pilgrimage many geocachers set themselves once in a lifetime: the headquarters of the game in Seattle, the commemorative plaque of the very first cache in Oregon (GCGV0P) and the last surviving Project A.P.E. cache in Washington State (GC1169).
Published in July 2004, it has been signed more than 22,500 times. Visits must be booked in advance and take place during office hours, Monday to Friday: it is probably the only geocache in the world whose main difficulty is finding a free slot in the calendar.
The answer : 2004