What is the most important object on my homestead?
Is it the well? Is it the barn...or maybe the workshop? Is it the creek, the pond or the swale?
Nope - its the survey boundary pegs! Objects to be found, respected and even revered. They define your land (and your neighbors) ad you just need to know where they all are (BEFORE you buy and maintan them afterwards).
I learned this through a bitter experience - and so I offer this advice to people so you don't end up in the same position we found ourselves in a few years ago.
One thing I tried first was a strong magnet with a telescoping handle. My place had been surveyed in the 70's so markers were out there. I knew the approximate locations of my 4 corners, but not exactly and they were out of sight in deep woods and brush. So armed with a shovel and magnet I went looking. After finding one I then used a compass to help trace one of my property lines and find the other. I found this vid by J and J acres very helpful https://www.youtube.com/watch?v=Z4yYHHX8N0A
Of course you can use a metal detector but I didn't want to rent one unless I had to