Came across this earlier today - an island which changes nationality every 6 months.
... put under "Assumptions programmers make about borders" I think!
https://www.bbc.com/reel/video/p0dff8mf/the-island-that-switches-nationality-every-six-months
The island that switches nationality every six months - BBC Reel

BBC Reel
@Sivation There's an island in the northwest passage that only recently had its border figured out. Technically Denmark and Canada were at war for years, and now we share a land border! It's wild.
@talarian aye; Hans island. They'd take turns leaving their flag & national spirit drink for each other from time to time!