The stretch of motorway below the cache is Watergrasshill's bypass. When the nearby toll road was built, it somehow ended up that one couldn't use the pre-existing bypass without paying the toll. And worse, to avoid the toll, which many still do, one had to drive through the centre of the village.
Today the toll-free bypass involves three roundabouts, crossing over the motorway twice, and low speed limits - a foretaste of what lies ahead on the road to Fermoy. Should one choose to go through the village, one will meet a special traffic light - unlike most others it goes red when it detects a car approaching.
The cache is a magnetic key holder next to one of the roundabouts.