Raumai Corner is a major part of local folklore, it is the centre of the entire world. Indeed, it is most often encountered in the phrase: "Well, first you go to Raumai Corner, then go..."
This major intersection links two important motorways, the first being the West Pohangina Motorway which runs from Ashhurst, through the major urban centres of Pohangina and Apiti, and then on to Auckland. The East Pohangina Expressway leaves at this point, and follows the opposite bank of the Pohangina River to skip the town of Pohangina and rejoin further north, providing a faster, alternate route to Apiti and points north.
Note that traffic has increased considerably in the last few years, these roads are now major expressways. Take care when retrieving the cache.