Those of you interested in the quirks of geography and borders may be interested in this article about Büsingen: http://www.bbc.com/travel/story/20190922-germanys-tiny-geographic-oddity
Büsingen is a German village surrounded by Swiss territory. The only way to get between Büsingen and the rest of Germany is via Switzerland.
Europe has a few of these quirks, usually with a history of rivalry between local lords behind them.
Other examples are Campione d'Italia (Italian village in Switzerland), Llivia (Spanish village in France), and the most confusing: Baarle-Nassau / Baarle-Hertog, a village divided into multiple Dutch and Belgian parcels: http://www.bbc.com/travel/story/20171210-europes-strange-border-anomaly
Living in such places used to be "interesting", customs and passport problems just to get in and out. Now with open borders they are just interesting curiosities.
Many in Easter Europe were abolished when borders were re-written after the Second World War, only to have a new ones appear when the Soviet Union splintered - Kaliningrad is the largest.
Plus there are cases where to get between two different places it is quicker to go via a different country. For example, trains from Vienna to western Austria (Tirol, Innsbruck) travel through Germany, as it is quicker to go round the Alps instead of through them. In the old days these operated as "sealed trains", they operated as a "bubble" of Austrian territory travelling through Germany. You did not go through passport control and you were not allowed on or off.