Between which two countries is there a land that no one owns?

The correct answer is Bir Tawil.

Explanation:

Bir Tawil is a small area located between Egypt and Sudan, which is in dispute for these two countries. It is said to be the only territory in the world (along with a small portion of the Antarctic), which does not belong to anyone. However, there are constant claims from these two countries that claim to have sovereignty in this territory, but this has not been settled in international courts. Bir Tawil forms a kind of triangle of approximately 2000 m2, and recently a US citizen named Jeremiah Heaton symbolically claimed his sovereignty over these lands to proclaim his little daughter as queen, but no state in the world has recognized him.