The first picture is of an N Scale (3x4) layout, which sold on Craigslist within an hour of posting. The reason for the N scale was the lack of room after downsizing into a smaller Townhouse.
The remainder of photographs are of a new Lionel "toy Train" layout (4x4) that I have just begun to build.
The wiring is "sandwiched" in a cavity between two pieces of plywood. Removable side panels allow the access. The advantage of this type of construction is that the layout can be placed on any flat surface, such as a table or even the floor.
If there is any interest, I will continue to post, as progress is made.