What is Letterboxing? It’s mainly a small container (usually made of plastic or metal), which contains a visitor’s book for messages and a stamp. These containers can be found by randomly searching or located using map and compass, we can provide both means of search. It’s one of the most unobtrusive ways to explore the wonders of Dartmoor whilst possibly catching glimpses of the local wildlife. Transport to and from this activity, bottled water and soft drinks are all included in the price.