Make a pilgrimage to the holy island of Iona and the historic abbey founded by St. Columba. Visit the abbey's museum, located in the former infirmary.
Facing its front door, walk around the right side of the building. Here you will find a small pile of rocks and building tiles. What you seek is beneath a V-shaped roofing tile, with a small rock for a door.
This may be a temporary pile of materials, so this may be a temporary box. But the pilgrimage to Iona is worth the trip in any case. Please let us know if you attempt or find this box; we would love to hear about your adventure: http://www.atlasquest.com/people/profile.html?gMemberId=1576