At the top of the Vee, the dramatic mountain pass that cuts through the Knockmealdown range between Counties Waterford and Tipperary, a small vaulted structure sits on an east-facing slope looking down over the road. It is recorded as a pill-box, a term that usually conjures images of concrete Second World War gun emplacements, but this building is rather different in character. It has a fireplace set into its west wall and narrow lights or loops, the kind of slim openings associated with observation or defence, in its north and south walls. The east wall no longer stands.

The structure measures roughly three metres east to west and just under two and a half metres north to south, with a maximum surviving height of about two and a half metres, and its vaulted roof sets it apart from any simple field shelter. What makes it particularly curious is its absence from the first edition Ordnance Survey six-inch map of 1840, which suggests it either predates systematic mapping and was simply missed, or that the survey team passed it by. The fireplace hints at something more than a purely military or watchtower function; whoever used this small vaulted room expected to be there long enough to need warmth. A related structure lies roughly 600 metres to the north, raising the possibility that the two formed part of the same arrangement for controlling or observing movement through the pass, one of the few natural corridors through the Knockmealdowns.