Paradise Ziplines is an eight-line, 1km zipline experience criss-crossing steep cliffs and cool blue pools on Rees Valley Station.
The set-up, which has been six years in the making, features a 100m drop.
Designer and owner Chris Russell, who also co-founded hugely-successful Canyon Swing Queenstown, does not want to talk sums but says it has taken a "big chunk" of money and "sweat equity".
Mr Russell roped in new operations boss Dave Anderson. Mr Anderson said they wandered the valley for weeks.
"You have to think about how it fits together," he said.
"The first line can take you to the second line. There is a certain gradient you have got to hit and you have to land on a feasible landing spot.
"But you can get seven lines in and then the last doesn’t work and you have to go back to the drawing board."
The first summer was spent scouting and putting in tricky initial lines.
They started out using fishing rods — casting the line as far as possible, finding the end, and hooking them up from either side.
Once an initial line was secure they fed a nylon cord on to it, which in turn was replaced by a steel cable.
All equipment, tools and supplies had to be lugged in by hand, including heavy wooden posts for platforms and a 35kg generator for power.
Once the first line was in they used it as a pulley to get gear up the gorge.
Mr Russell was excited they were ready for punters and already had plans to add a bungy jump.
"People will get hauled up from the river bed in a cage ... a magic lift goes up and you jump straight out. Simple."
The zipline activity will cost $179 per person, including Queenstown transfers.
