I have no idea what this tiny building, situated on a main road, was for.
It dates from around the mid-1800's and has a lovely fireplace.
The dimensions are about 4m x 2.5m.

Scavenger-Hunters are here http://forum.pbase.com/viewtopic.php?f=16&t=43593&sid=44cd4769f1a74ee7d7655ac590ba6aaf