I was mesmerised by the contrasting colours and characters of the lakes, the palisade of mountains encircling us, and the long shadows cast by the late afternoon sun.
The boat trip from Wanaka to Mou Waho (meaning Outer Island) only took about 30 minutes and the climb to the top just 40 minutes, but the island felt seriously remote.
Tucked behind a high mountain range, it's out of sight of the township. Standing on Tyrwhitt Peak (473m), the rocky summit of the island, there were no signs of human habitation. I couldn't understand why, after umpteen years of holidaying in Wanaka, we had never been to this remarkable place.
We were effusive in our thanks to our friends who beamed with satisfaction at having added another treasure to our Wanaka collection.
But there's more to the Mou Waho than its breath-taking beauty and Russian doll-esque lake-on-an-island-on-a-lake claim to fame.
Mou Waho (120 hectares), the largest of four islands on Lake Wanaka, is a scenic reserve where small miracles are taking place.
The island is uninhabited now but in the mid-1800s and early 1900s, it was used as a base for boat building and sheep grazing. Remnants of a stone wharf and cottage can still be seen there.
Managed by the Department of Conservation (DOC), the island is predator-free and is a haven for species that have disappeared from the adjacent mainland. Native birds, plants, insects and other wildlife flourish on Mou Waho safe from stoats, rats, ferrets and possums.
A joint project between Te Rūnanga o Ngāi Tahu and DOC introduced the rare flightless Buff Weka to the island in 2004. Extinct on the Mainland since 1920, the population is thriving on Mou Waho. Soon after we arrived on the island, we met the first of many famously-feisty, curious weka, popping in and out of the bush in search of food.
We also came across some rustic little motels. There are 40 of them on the island but you would not want to stay in them . . . they are full of creepy-crawlies. The hollowed out tree trunks were purpose-built in 2012 by students at Wanaka's Mount Aspiring College in conjunction with DOC and Eco Wanaka Adventures to protect the endangered Mountain Stone Weta from the Buff Weka. The accommodation is quite luxurious, if you are a weta. Another exceptional success story on the island.
The Southern Alps gecko is also doing well on the island but they are shy creatures so we did not see them.
There's a toilet near the landing site and camping is allowed on the island so next time we'll bring our tent and hang out with the wekas. Hopefully the wetas will stay put in their own motels.
Soaking in the spa pool under the stars at the lovely Te Ariki Nui rural retreat near Wanaka where we were staying for the week, I thought how blessed we are in this country to be able to experience such a wonderful wilderness so easily and for free . . . apart from petrol for our friends' jetboat and a few cold beers to drink on the beach.
Checklist: Wanaka
• Te Ariki Nui is 15 minutes' drive from Wanaka. The four-bedroom, three-bathroom house surrounded by 4 hectares of orchards, tussock-lands and alpacas, was designed by award-winning architect architect Paul Clarke and was runner-up in the 2005 New Zealand Home & Entertaining Home of the Year Award.
• Air New Zealand flies daily to Queenstown from Auckland, Wellington and Christchurch with connections available across the domestic network.
• Pick up a JUCY Rental at Queenstown Airport and drive to Wanaka - 60 minutes over the Crown Range or 90 minutes via the Kawarau Gorge, both magnificent scenic experiences.