Anai Waterfall, Cascade waterfall in Singgalang, Indonesia

Anai Waterfall is a cascade waterfall in Singgalang, Indonesia that drops roughly 35 meters from the Batang Lurah River. The water flows through dense forest at the base of Mount Singgalang, forming a natural boundary of the Anai Valley Nature Reserve.

The waterfall sits beside the old Padang–Bukittinggi road, next to a bridge and a disused railway line, and was long recorded under the older spelling Ajer Mantjoer. Its position on that colonial-era route made it a roadside landmark between the coast and the highlands.

The site is valued by locals as part of Sumatra's natural landscape and serves as a habitat for monkeys and other forest creatures. Visitors can observe these animals in their natural setting while exploring the forest.

Anai Waterfall sits directly on the Padang–Bukittinggi road at the foot of Mount Tandikat, beside an old railway line and bridge that are no longer in use. A large parking area is available for visitors arriving by car. During heavy rain the river can swell and overflow onto the road, so check conditions before setting out.

The old spelling Ajer Mantjoer survives in the name of the jorong Aie Mancua where the fall stands. The flow is strong and steady in the rainy season but swells greatly during heavy rain, and the river sometimes floods and spills onto the Padang–Bukittinggi road.