Perched high on the ranges between Lakes Rotoiti and Rotoroa in Nelson Lakes National Park is Rotomaninitua / Lake Angelus. It is really a large alpine pond or tarn, a legacy of recent ice advances and typical of the many tarns in the park.
During successive major ice advances, which ended about 10,000 years ago, glaciers and permanent snowfields covered much of the Southern Alps. Erosion by ice has left its characteristic mark: steep valley walls, bluff-ringed side creeks, sharp ridges and peaks, and round, lake-filled basins.
The trip along Robert Ridge to the lake is one way to enjoy the alpine environment in the park. The first recorded person to scramble along Robert Ridge was Julius von Haast in 1860 but it is unlikely he was the first.
The lake was previously known as Rangimarie (a Maori name given by a European meaning peaceful). Later a group climbing the obvious peak to the south named the peak and by association the lake ‘Angelus’ after a devotional prayer. They also named nearby Hinapouri Tarn (dark waters), and Hukere Stream (cascading waters).