Letterboxing started in Dartmoor, UK long before selective availability got turned off and Geocaching began, 'caches' or 'letterboxes' were shared by word of mouth and locations were described rather than found via coordinates. Also each one has a stamp in it.
Follow the instructions to find the cache:
Start at the listed coordinates and walk to N53° 46.441' W000° 47.413' (Waypoint 1)
From here you will be able to see a white & green barn, and also two green silos (round ended cylinders).
Continue West along the bridleway until the edge wall of the barn is in between the silos (used to be where the barn and the right hand silo touch, but they built another silo to the left), then head North in to the bushes!
(If you come upon a wire fence blocking your way you have not gone far enough West.)
There is a shallow ditch that may fill in winter, Among the roots of the trees near a corner in the ditch there is a curved ridge tile, the letterbox cache is underneath it.
Please leave the stamp in the cache, it is part of what makes it the letterbox!
This cache was named because we recently bought some caterpillars which grew into butterflies and were released nearby. Unfortunately farmers pesticides reduce the amount of caterpillars that make it in to butterflies, although you should find at least one today!