Have you ever heard of the folk tale steak your claim? This is where it's from. Railroad spikes have been used for centuries to protect your land. Place spikes in the 4 corners of your property and set your intentions.  I've had people write on them things such as " All who work on this property must be in their integrity" to "No one can ever evict me." Place in your closet to close a portal or in your trailer to protect you from predators. These are heat activated and resy for you to set. Someone would ha e to dig them up and put them and do heavy work to remove that magic.