Here are my "hardest of the hard clusters" - the least evangelized people clusters, based on data from the World Christian Encyclopedia/World Christian Database. Be sure to follow the Center for the Study of Global Christianity (@CSGC) for great stats and data.Nuristani. Centered primarily a very difficult to reach portion of Afghanistan, a people cluster of about 100,000, less than 5% of whom are estimated to have heard the Gospel. There have been many, many martyrs among those who have tried to reach out to them, especially in the last 10 years. Much prayer needed, and much careful spending of effort. Zenaga. A small cluster of several thousand people in North Africa. Also known as the Sanhaja. This used to be one of the largest Berber tribal confederations along the Maghreb. Related to the Sahrawi (Saharawi). Bozo. Somewhere between 25,000 and 100,000 depending on who is counting. Primarily along the Niger River in Mali. Mostly Muslim with animist traditions. Gurung. Population uncertain, with estimates ranging from 250,000 up to several million depending on how they are counted. Primarily along the India-Nepal-Bhutan line in the southern Himalayas, mostly living in Nepal's mountain valleys. Mostly Buddhists. Kirati (Rai). About 800,000, also in the area of Nepal. Mostly shamanists following a "Kirat religion" characterized by nature and ancestor worship.