I've got permission to hunt a swamp that is now land locked. I hunted it for years before they built houses right where my access was.
I could still access it by using my 4 wheeler and coming in through some power lines, but I've aggrivated the deer hunters who hunt that area (by busting woodies while they were hunting in their stands)
I had a confrontation with one of them once, and I doubt I could talk them into letting me through. I don't know who actually owns that land.
I really miss that spot though. It was close to work, and I could hunt it before work from time to time. It's definately land locked. The owner sold it all but the swamp.