No, the main structure is actually a hikers/Trampers hut built for overnight stays by hikers on multi day hikes in the area. They've maintained by either the Department of Conservation, or Parks and Wildlife, can't remember exactly. They've usually got a grassed/cleared area around them to allow for tents to be pitched as well.
They're stocked with a bit of firewood, and some might even have the odd cooking utensil. I'll post a couple of photos from inside. There's actually a cleared Helicopter landing area pretty close by, I only know that because there's signage telling hikers not to camp there for obvious reasons:)
The hut/toilet is right up the top of those ridges in the distance, nestled in one of the saddles. Decent walk in and out in a day, that's about half way in