You may want to check with your lawyer about the following if purchasing a large plot of land.
Squatters
If you own or plan to own a large property like 6 or more acres and do not visit the entire area often, you may end up with Squatters. The longer they stay the harder it is going to be to evict them, specially if they build a permanent home. So keep an eye on the land, specially land that is far from view.
My brother has 8 acres and about 2 years ago found somebody building some shack in his property to raise chickens and had to go thru the trouble of getting them removed. Luckily he had the land rented to the local milk production company and they used their lawyers to have them removed so he did not had to spend money getting lawyers.
Before you buy, make sure you walk the entire property and view your property markers.
Environmental Issues
Trees in your property may require a permit to be removed, check on that. Typically if they are deceased there is no issue, but check. Swampy areas can also cause you problems if you want to eliminate them and any natural body of water.
Access Rights
Also check for passage/access rights, other properties around you may have a right of passage because the other properties may not have access to a road, so they may have the right to create a private road thru part of your property.
Rivers in your property and beach front
If you have a beach front property, there has to be a way for the public to reach the water, beaches to my knowledge are public space so they have have the right to be able to access it.
Rivers and lesser water causes are also considered public, a person can walk inside the river area thru your property and that to my knowledge is legal. They can not come out of the banks into your property but they can use the river and walk it up and down all they want.
Disclaimer
I am not a lawyer. Check with our lawyer before you buy if the above still apply, things could have changed and the above no longer be applicable. Better to know of any restriction before you put down your money.
My knowledge is based on some personal experiences and family that have gone thru some of it.
I may or may not be able to answer much past the above. This is just a heads up. Know before you buy.
Rey