Lake Quill is a tarn located in New Zealand's Fiordland National Park at 979 m above sea level. The cirque lake of approximately 1.2 km² is the source of Sutherland Falls, one of the highest waterfalls in the country and seventh-highest in the world, cascading from Lake Quill in three tiers into the Arthur Valley alongside the Milford Track, approximately 20 km fr…Lake Quill is a tarn located in New Zealand's Fiordland National Park at 979 m above sea level. The cirque lake of approximately 1.2 km² is the source of Sutherland Falls, one of the highest waterfalls in the country and seventh-highest in the world, cascading from Lake Quill in three tiers into the Arthur Valley alongside the Milford Track, approximately 20 km from Milford Sound. It is believed that the lake is formed by the movement of glaciers during the last ice age.