Copy some random bridge(any will work). Then replace the model with Wall End Low.
Voila, you have a square platform.
Don't forget to remove pathing or use the one that circle of power has.
Overall, Wall End Low is a very versatile model. If you use it as a doodad you can resize it into a tile by making it low, or wall by making it high.
Bookshelves can be used as wooden walkways.
The upper left corner of the attached map is an example.