The Caprivi Strip

The country of Namibia has a sizeable landmass with an enviable coastline by the South Atlantic Ocean. Yet, a thin sliver of land, no more than 32 kilometers wide, protrude eastward for about 450 kilometers from the north-eastern corner of the country towards Zimbabwe, seeking something it doesn’t have. This odd finger-like intrusion is called the Caprivi Strip, after German Chancellor Leo von Caprivi, who negotiated the acquisition of the land with the United Kingdom in 1890.

The Heligoland–Zanzibar Treaty, signed between Great Britain and the German Empire, gave Germany control of the islands of Heligoland in the North Sea and the coast of Dar es Salaam that would form the core of German East Africa. In return, Germany handed over to Britain the islands of Zanzibar and parts of East Africa. Thrown along with the deal, in favor of Germany, was the Caprivi Strip which connected the German South West Africa to the Zambezi River. This gave Germany a route to Africa's east coast, where the colony of German East Africa was situated. Except it didn’t. Leo von Caprivi was not aware that the Zambezi River was unnavigable. Just 80 kilometers downstream was a major obstacle—the world’s largest waterfalls, Victoria.

When Germany realized their mistake, they tried to swap the Strip for another British territory, but the British were not interested. Caprivi’s predecessor Otto von Bismarck attacked Caprivi over the failed deal, remarking that Germany had traded away its entire “trousers for a button.” But the island-swap was not completely bust. Although they lost the “Scramble for Africa”, Germany acquired Heligoland, strategically placed for control over the German Bight, which, with the construction of the Kiel Canal from 1887 onward, had become essential to Emperor Wilhelm's II plans for expansion of the Imperial Navy.

References:
# CN Traveler, https://www.cntraveler.com/stories/2013-03-04/caprivi-strip-namibia-zimbabwe-maphead-ken-jennings
# NY Times, https://web.archive.org/web/20131017020632/http://opinionator.blogs.nytimes.com/2011/12/05/a-few-salient-points/?_r=0
# Wikipedia, https://en.wikipedia.org/wiki/Caprivi_Strip