Roaring Billy Falls is a 30-metre (98 ft) cascade tucked into the Haast River valley within Mount Aspiring National Park, about 30 km inland from Haast township along State Highway 6.

The falls tumble down a jumble of moss-covered boulders before emptying into the broad, boulder-strewn bed of the Haast River at an elevation of roughly 80 metres. A short, easy walking track — approximately 1.

4 km return — leads from the highway car park through lush native rainforest to a viewing area on the riverbank. The contrast between the dense rainforest backdrop and the wide gravel flats of the Haast River makes the setting particularly striking.

The falls are audible well before they come into view, and their roar intensifies after heavy rainfall.