Sipisopiso Waterfall located 3 hours from Swiss-Belinn Medan an can be reach by driving via Jalan Sidikalang - Medan, depends on current traffic.
The Sipisopiso is a plunge waterfall in the Batak highlands of Sumatra. It is formed by a small underground river of the Karo plateau that hurls itself from a cave in the side of the lake Toba caldera some 120 meters (360 feet) down to lake level. This fact earns it the title for the highest waterfall in Indonesia. Sipisopiso is a well-known tourist attraction and a nearby vantage point offers great vistas of the fall and the lake.
Sipisopiso waterfall is located in the Tanah Karo regency, at the northernmost tip of the Lake Toba caldera, near the fishing village of Tongging. The closest municipality, about 25 kilometers away, is the town of Kabanjahe.
Source: https://en.wikipedia.org/wiki/Sipisopiso