MOUNT VERNON — It’s part treasure hunt, part artistic expression.

It involves navigation and the willingness to explore remote destinations.

It also spans the ages as young and old take part alongside each other.

And it was all started by a man in England who simply left his calling card in a bottle by a pond on the moors of Dartmoor.

Welcome to the world of letterboxing, an elaborate game of hide and seek.Read The Full Story