Who are the Land owners?

[Razoromero]

Hi everyone. I was wondering how you go about finding out who owns pieces of land out in the sticks? Not fields and farmland as such but the apparently wild, overgrown wooded areas in all the spaces between towns and villages etc. Say I wanted to go out camping with my son to practice bushcraft skills I would want to be able to light fires, fish, build shelters and stuff without risking getting into bother like trespassing and cries of "Get orf moi laaaand!"
I mean, where can you go carrying knives and fire starting kits without getting hassled by anyone?

Cheers!