After WWI, the government sponsored a number of soldiers’ families to continue up the Kaiwhakauka Valley from Whakahoro and establish farms. This venture failed miserably, and by the 1930s, everyone had left. Now, it’s largely a regenerating forest.
You can walk up the old road for an hour or so to connect with the Pariatua Trek, which climbs high up into the station, or continue on to connect with Te Araroa, then all the way to Mangaparua Landing (more than a day with several campsite options). To continue, a prearranged boat pick-up is required. Close to the turn-off to the Mako Mako Track is a restored “house” of the kind that was built for early settlers. Thankfully, times have changed.
The Kaiwhakauka to Mangaparua Landing is also part of the Mountains to Sea cycle trail.