
If you claim the inside of a cave and then put up a stick gate right in front of it, you can prevent people from passing through it completely. Even vandalism is useless due to exploiting the visitor buff in this instance.
This takes a few minutes to do, and is impossible to get around without:
A - Minehole (Extremely resource intensive at this point in the game)
B - Mining in from another cave.
C - Finding another entrance.
This abuse seems way too easy to complete for the safety it gives you.