Absentee landowners are the best, those that are either snowbirds or just left.
Go down to your county offices and get a land plat map or book.
This tells you who owns what.
And often their mailing address.
Caching in various locations can be easy or the most amazing chore. Much depends on the climate and weather.
But in general you want to be far enough off the beaten path that being observed is unlikely. The last cache I helped with had 10- 5 gallon buckets in it. All the gear was vacuum packed in mylar and both nitrogen and O2 absorbers were used. Overkill perhaps, but this is a long term cache. 20+ years.
A variety of old mining junk is scattered through the area so detection is unlikely, and the junk is used to open the cache itself, anchoring off one piece to slide the cover off.
Another used a series of SDR tubes to hold the inner tubes, a bit of wasted space and pricey, the owner can uncap the tubes and move the contents with minimal effort when he changes areas. This happens about every year, thanks to his job.
Depending on your area, that nosey neighbor may be an anti gunner, who better to store stuff for us? One friend ended up helping the nosey neighbor put in a birdwatching bench out in the back 20.
She actually paid him to prep the land.
The cache is under 3″ of concrete, shaped like real stone with appropriate cuts and cracks for removal later if needed.
The site overlooks his property so he knows if anything is happening to it and and can act accordingly.