Tongging is a perfect place to relax. It is located in the far northern end of Lake Toba in a dramatic setting. The climate is perfect here, 900m above sea level, the landscape is fascinating, and the culture unique. Lake Toba is a perfect destination for kayaking.
There is plenty to see and do; the biggest waterfall in North Sumatra, traditional villages, swimming, walking, trekking, kayaking and more. Besides that, Tongging has a strategic location in between other destinations and therefore a nice and practical stop over, for example if you go from Medan or Berastagi to Pulau Banyak.
It is only a three hour car ride to get there. Tongging can be recommended, both for the adventurous travelers and the travelers preferring some conveniences. It is a popular place amongst locals on weekends and public holidays. Most of the locals are farmers, growing onions, garlic, mangos and more. Fish farms have become popular, especially for gold fish and Gurami. Tongging is in the middle of an area where the three ethnic groups Batak Toba, Pakpak, and Karo have mixed completely. The local language uses words from all three ethnic groups.
Quoted from http://www.sumatraecotourism.com/tongging/index.html