Irrational Number Line Games, LLC
Two nice bits for conversion.
First, the spray can cap. I use a lot of spray primer and base coatings, so I have a lot of caps. Some are plain cylinders. Some have these grips on them. Other are tapered, with or without grips. If you have a textured spray paint, the cap usually already comes textured.
And a good old juice bottle lid. Again, I have some and will have more. These are from Simply juice, and have a nice geometric grip design that will work well for architectural design.
I just glued the caps together and painted them up. Though some of the caps come textured, I use sand and wood glue in the paint to give them a stone like texture. A black wash brings out the shadows.
The grips make nice inset windows.
Of course, if we want to put figures on the top of these, we need a hatch to get from the inside to the top. This is just basic thin card with wood patterns done in black ink. When I paint them with various shades of brown, the ink will bleed through and shade in the grooves made by the ball point pen.
But we don't go in through the windows, so we need doors.
First, cut out a 1" diameter circle. Use a big hole punch if you have one. If not, a soda bottle cap is about the right size.
Then cut up from the bottom to the sides of the circle to make a rounded-top door shape.
Use this as a template to make door shapes that will match each other. Sometimes you want uniformity if you will have two or three towers in the same location.
Now do the door decoration bit.
So we get doors. Take them in your fingers, then bend them a little bit so they will git against the curved surface of the spray can caps.
And you get historical or fantasy towers with nice crenolations on top!
If you add a half of a plastic easter egg or use two juice caps of different sizes, you can get different designs.
And that's just the start. Pretty much anything round of roughly this size will give you your own unique tower.
This makes a nice vantage point.
Or a strategic location to protect.
And you can even go simpler for a more sci fi look.