Park at River Road carpark (marked as a waypoint).
This is an easy, short (about 15min) well graded walk which follows the start of the Whirinaki Track to the spectacular "big canyon of Toi". The forest is rich with birds and plants, including spectacular views of all five huge podocarp species.
More info on the Whirinaki Track and Whirinaki Forest Park:
http://www.doc.govt.nz/parks-and-recreation/tracks-and-walks/east-coast/te-urewera/whirinaki-track
http://www.doc.govt.nz/Documents/parks-and-recreation/tracks-and-walks/east-coast-hawkes-bay/walks-in-whirinaki.pdf
No need to go bush bashing, cache is approx. 1m off the track. Marking the waypoint for this hide was a bit tricky due to trees etc. so you may need the hint ;)
Happy Hunting!