Piroa Falls are situated in the Waipu Gorge scenic reserve on Gorge Road (metal road for the last few kilometres) with a pleasant 10 minute walk to the falls through the bush. The lat/long takes you to the general area. 
(Much of the development has been thanks to the work of Maungaturoto Rotary.) The falls are spectacular and there is a good picnic spot with seating and a table. There is great scenery and excellent swimming holes so take your lunch and togs. The area is signposted on SH 1 at the northern foot of the Brynderwyn hills.
Due to the thick bush cover gps coverage is poor. From the bend in the track there is a small trail that heads up the hill, follow this trail up about 15m and the cache will be at your feet. container is a small 200ml systema.