A few people in my neighborhood have fences/walls. Most are those incredibly ugly white plastic things. I know where my corner markers are. I try not to put stuff beyond my boundary, but it generally doesn't really make a difference as three sides of my property is wooded/wild, and I'm probably the only person to go in there. The town "owns" 10' on either side of the road in front, so I try not to put much there except for my mailbox and a couple of small flower patches. Note: Kids do not recognize boundaries. They will ride their bikes on my driveway, across my yard, wherever they feel like it. Smart people, those kids.