Worth adding, at least in some countries, the laws allow physical squatters to legally take over ownership of land or property, if they can document they lived there / put it to productive use over many years (IIRC 20, in Poland), while the original owner didn't use it in any way.

EDIT:

https://en.wikipedia.org/wiki/Usucaption

https://en.wikipedia.org/wiki/Adverse_possession