Everything changes. The top of Mount Everest was once on the seabed. You could have paddled barefoot on its summit without getting frostbite. Sharks would be a different matter.
Borders change, then change again, and again. A third of the world's frontiers are less than 100 years old, and many of those were part of the 'Scramble for Africa', when the presence of natural resources often led to trouble. Diamonds are a girl's best friend.
Territorial jurisdiction has often changed hands through war, marriage and just plain indifference - or extravagance, in the case of Cyprus, which Mark Antony gave to Cleopatra as a wedding present. Seven sovereign states have claims to pie-slice sections of Antarctica, brr! The USA bought Alaska from Russia for $7.2 million, and Belgium and the Netherlands once swapped land to sort out a complex river border. India and Bangladesh did a similar deal involving enclaves within enclaves.
There are some exceptions to boundary upheaval. The border between Spain and Andorra has remained unchanged since 1278, when a feudal charter 'solidified Andorra's geography', likewise the Portugal-Spain border has been in place since 1297. Yugoslavia had all of its borders taken away, and frontier fortifications known as 'limes' marked the edges of the Roman Empire before it declined and fell.
And then we come to the strange case of Europe's newest state, a 'micronation' in the Balkans, between Croatia and Serbia on the western part of the Danube river. The fact that Serbia and Croatia had been unable to agree on common borders for 25 years led to the creation of Liberland in April 2015. It has no diplomatic recognition from any other nation. It lacks infrastructure and lies in a floodplain. Taxes are optional (!) and there is no military. I'm guessing it has no twin towns or sister cities.
Croatia blocked people's access to Liberland a month after it was founded, so the population remains small - probably just as well, since the entire 'nation' is only 7 square kilometres in size. Even so, some people have already made plans to relocate there. Will they be taking their brains with them?
Liberland's motto is "To Live and Let Live," not something James Bond would approve of, and it rather optimistically offers a 'First Class Order of Merit' to persons who have contributed to its development, by discovering oil there, or by draining its floodplain. And also by "spreading news about Liberland throughout the world at large." Who knows, my O.M. First Class may soon be in the post. Oh no, I forgot, Liberland doesn't have a post office.
