Take a point in space. Make believe it is a magical permanent marker point. Now move the point in a direction. When you're done moving it we'll see a magic marker line. Now move the magic marker line and when your done we'll have a magic marker plane hanging out somehwere up above. Take the magic marker plane and move it through space and we have a solid. Now move the solid and whether the trailing edge or leading plane of the solid is the permanent magic marker or the entire solid is we will see what?:-}
My limited brain simply sees another solid. But if there is a fourth spatial dimension then there are certainly n more dimension and n more headaches to contend with.
Now back to the three dimensional fence on the southern border in real time.