Four-nation Quadripoints
While some older sources claimed that a quadripoint existed in Africa, where the borders of Namibia, Botswana, Zambia, and Zimbabwe come together at the confluence of the Cuando (also called Chobe) and Zambezi rivers (approximately 17°47′30″S 25°15′48″E / 17.79167°S 25.26333°E / -17.79167; 25.26333), it is now generally believed that two separate trijunctions exist perhaps some 100 or 150 meters apart.
In August 2007 the governments of Zambia and Botswana announced a deal to construct a bridge at the site to replace a ferry. The existence of a short boundary of about 150 meters between Zambia and Botswana was apparently agreed during various meetings involving heads of state and/or officials from all four states in the 2006–10 period and is clearly shown in the African Development Fund project map (matching the US Department of State Office of the Geographer depiction in Google Earth).
There have been a few international incidents revolving round this particular quadripoint, or near-quadripoint. In 1970, South Africa (which at the time occupied Namibia) informed Botswana that there was no common border between Botswana and Zambia, claiming that a quadripoint existed. As a result, South Africa claimed, the Kazungula Ferry, which links Botswana and Zambia at the quadripoint, was illegal. Botswana firmly rejected both claims. There was actually a confrontation and shots were fired at the ferry; some years later, the Rhodesian Army attacked and sank the ferry, maintaining that it was serving military purposes.
Ian Brownlie, who studied the case, wrote in 1979 that the possibility of a quadripoint could not be definitively ruled out at that time.
However a true four-country point did formerly exist in Africa – indeed (if we exclude the one at Kazungula) the only known quadricountry borderpoint (not involving condominial territories) – for a period of 8 months during 1960 and 1961, in southern Lake Chad, at the location of the present Cameroon–Chad–Nigeria tripoint, where the latter three countries were then also joined by a territory called Northern Cameroons which still belonged, under United Nations mandate, to the United Kingdom, until it was finally integrated into Nigeria. (It should perhaps be noted that this particular geographical multipoint, though notional since 1908 if not 1891 and definitely fixed and fully agreed since 1931, remains undemarcated if not also undatumized to this day.)
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