In the realm of international geopolitics, nations usually fight fiercely over every square inch of territory. Bir Tawil, a trapezoidal expanse of sand and rock in North Africa, is the world's premier exception. It is one of the very few places on Earth unclaimed by any sovereign state—a true terra nullius.
The reason for this strange abandoned status boils down to a diplomatic game of reverse hot potato created by the British Empire. In 1899, the United Kingdom set the political border between Egypt and Sudan along the 22nd parallel north, placing Bir Tawil in Sudan and the fertile, coastally strategic Hala'ib Triangle in Egypt. However, in 1902, the British drew a separate administrative boundary.
This revised map handed administrative control of Hala'ib to Sudan, while Bir Tawil was given to Egypt. Herein lies the technicality: Egypt recognizes the strict 1899 border, which grants them the prized Hala'ib Triangle and leaves Bir Tawil to Sudan. Meanwhile, Sudan recognizes the 1902 administrative border, which awards them Hala'ib and dumps Bir Tawil on Egypt.
Because the far larger and resource-rich Hala'ib Triangle sits on the Red Sea and contains valuable mineral deposits, neither country wants to assert sovereignty over Bir Tawil. Doing so would legally invalidate their respective claims to Hala'ib. Consequently, Bir Tawil remains completely officially unclaimed.
Over the years, eccentric tourists and micronation enthusiasts have trekked into the desert to plant custom flags and declare themselves monarchs—such as an American father who claimed it so his daughter could be a real princess—but international law remains entirely unimpressed by these self-proclaimed kingdoms.