Lake Waikareiti was formed by a massive landslide which took place about 18,000 years ago. A thick slab of country 10 km wide slid off high ridges in the north-west, depositing uneven debris over a wide area. Lake Waikareiti and several lakelets formed in hollows in the debris. The lake is free of pollution and all introduced aquatic plants, and has remarkable water clarity. The islands in the lake are possum-free allowing rare red and yellow-flowered mistletoes to flourish. Rahui Island features an unusual "lake-on-an-island-in-a-lake".
You may hear two of NZ's increasingly endangered parrots: the screech of the kaka (the forest relative of the South Island alpine Kea) and the chatty ki-ki-ki of the yellow-crowned parakeet (kakariki). Listen too for smaller but equally remarkable forest birds: the rifleman/titipounamu (which weighs a mere 6 grams and measures 80 mm in length), the tomtit/miromiro (which can spot an insect as far away as 12 m) and the inquisitive North Island robin/toutouwai.