The closest car park to the cache is a one hour walk (one way) at the end of the Monowai Road. The track from here to the cache is well formed and marked, relatively flat and suitable for most people. The tracks from here heading towards Rodger Inlet Hut and Green Lake Hut are significantly more challenging and should be attempted by experienced trampers only and preferably with a group. Remember to tell someone where you are going as there is no cellphone coverage in the area.
More ambitious cachers could approach it from the start of the Green Lake Track on Borland Road - this would take about 6-7 hours but an overnight stay at Green Lake Hut is highly recommended. It is one of the jewels in Fiordland's crown. Waypoints for both trailheads have been provided.
Check the weather before you go out, download or buy a map, and check the track conditions and information on the DOC links provided below:
Rodger Inlet Track: http://www.doc.govt.nz/parks-and-recreation/tracks-and-walks/fiordland/southern-fiordland/rodger-inlet-track/
Green Lake Track: http://www.doc.govt.nz/parks-and-recreation/tracks-and-walks/fiordland/southern-fiordland/green-lake-track/
There is DOC hut accommodation available at Rodger Inlet (6 bunks) and at Green Lake (12 bunks).
If you have time, I would recommend staying a night at both, as I have also placed Geocaches near both of these huts.
This cache is situated in a truly beautiful part of New Zealand, seldom visited by locals and tourists alike, so if you are looking for a moderately challenging tramping experience in uncrowded and unspoiled wilderness, with a few caches to pick up on the way, you have found it!