Grojogan Sewu waterfall, Natural waterfall in Tawangmangu, Indonesia

Grojogan Sewu is a waterfall in Tawangmangu, Indonesia, flowing in several tiers down a cliff face surrounded by dense rainforest. The water drops from a height of 81 meters (265 feet) on a plateau located at 1,200 meters (3,900 feet) above sea level.

Grojogan Sewu lies on the southern slopes of Mount Lawu, about 27 km east of Karanganyar, and its stream joins the Bengawan Solo via the Kali Samin at Tegalmade. The site forms part of the 20-hectare Grojogan Sewu tourist forest, which is planted with many kinds of forest trees and is home to a group of tame monkeys. Facilities in the forest include a forest animal park, a swimming pool, rest areas, food and fruit stalls, souvenir kiosks, a mushola and toilets.

In Javanese, grojogan means waterfall and sèwu means thousand; the name refers to a thousand pecak, an old unit equal to one adult footprint, used to measure the falls' height. Local myth holds that unmarried couples who cross the bridge in front of the waterfall will see their relationship end before marriage.

Two entry points lead to the falls: one near Balekambang Park with 1,000 steps, the other near River Hill with a gentler slope. The stepped path requires more effort but offers viewpoints along the way.

Wild monkeys live in the surrounding forest and move freely among visitors while searching for food along the paths. The animals have grown accustomed to human presence and show little fear.