The victory over the Mahdist forces of the Khalifa at the Battle of Omdurman led to the establishment of a hybrid form of rule over the Sudan for the next 56 years and the establishment of the borders of the country as they were until 2011. This odd creation needs to be understood because its boundaries could not be set or changed by one imperial power alone, in this case Great Britain, but, in principle at least, had to receive the consent of the other “Codominus”, in this case Egypt.The Ilemi Triangle is a territory of 10-14,000 km² (so roughly the size of Flanders, Connecticut, Lebanon, Jamaica or Montenegro) whose borders with Kenya, Ethiopia and South Sudan (previously Sudan) have never been properly defined. Ethiopia does not claim it as sovereign territory, but both South Sudan and Kenya do. It is not very clear how many people live there. Kenya counts it as part of Turkana County, and South Sudan counts it as Eastern Equatoria State, both of which have a population density of roughly 13 per km², so probably there are 100-150,000 inhabitants given that there are no towns of any real size. In any case they are mostly transient pastoralists. Google Maps knows of four settlements in the area, Lokomarinyang, Kibish, Napak and Kokuro; going by the satellite pictures, none of them has a permanent population very far into three figures.
Philip Winter looks at the history of how this particular territory fell through the cracks of cartography. It's a narrative interwoven with personal reflection; here's a representative footnote:
Writing in 1975 [Sudanese scholar Faisal Abdel Rahman Ali Taha] suggests that Mt. Tomadur, a mountain on the Sudan-Ethiopia border some 40km north east of Mt. Naita is the northernmost point of the Triangle. The author climbed this mountain in 1998 and found no sign of any presence of any government whatsoever, Sudanese, Kenyan or Ethiopian, no trig point and no beacon. When the author climbed Mt. Naita some two years later, there was also no trace of any previous visits by anyone at all, let alone of any beacon or a marker.Fundamentally, it was too far away to be of much concern to the heads of government in Nairobi, Khartoum, Juba or Addis Ababa, all of which had other more pressing problems to deal with, both internally and in terms of their mutual relationships. South Sudan still claims the entire territory de jure, but de facto Kenya has a monopoly on the legitimate use of force (though this could easily be contested by either neighbour, and has been on occasion). Philip Winter chronicles a list of border resolution processes over the decades which simply failed to reach a decision. Both Juba and Nairobi are committed in theory to coming to an agreement, but pressure of other business has prevented this from happening.
There is, of course, an sfnal connection; in the Marvel Universe, the Ilemi Triangle is the location of the kingdom of Wakandsa, ruled by T'Challa, better known as Black Panther. Frankly, it does sound like one of the few places on earth where you could hide a high-tech civilisation without anyone much noticing.