View Full Version : Pentagonal Keep

02-05-2013, 11:03 AM
What do you call a pentagon made of pentagons?

A mapping challenge!


So the idea was to take a series of pentagons and tie them together within a pentagon and create a fortress out of it. The first draft (above) was just to hammer out some basic functional design issues. I wanted to figure out how people were able to get up and down through the many floors of the fortress so I decided that the central pentagon would be something of an open space (like a sun well) with stars. It would bring in plenty of light and, hopefully, make the inside of the fortress appear less gloomy.

Once movement was sort of figured out I thought that I would try populating the spaces with various room elements to see what happened.


So I added a basic barbican or gatehouse to the space between two pentagons and then tried to fill in some spaces with tables for a dining hall and bookshelves for a library.

It's not...wrong but still doesn't feel right.

So then I decided that I'd take a different perspective and fool with the shape itself and see what shook loose.

Rather than running to Google Sketchup I tried to use some of the tips on creating an isomorphic map. This gave me an idea for how the design would look once rendered into a third dimension and I started to like it more.

After duplicating the levels I ended up with something like this:

I'm not sure if I like the straight-sided walls of this version or if it would be better to gradually decrease the size of the pentagon...florette? So that it becomes a 'stepped' fortress.

I read that stepped structures more evenly distribute the weight of the upper floors but I'm not sure if that would apply for a shape like this.

Any suggestions on the wall-sides? Stepped or straight?


02-05-2013, 11:53 AM
I couldn't help myself. I had to throw this into sketchup and get some sense of scale.


Basic theme has been replicated and I like the look of it.

But I had no idea how big the walls would have to be to accommodate the design.

Originally the idea was to have the entrance between two of the pentagonal shapes. To accomplish this I used the scale tool and kept making the whole shape larger until the tiny wall between the two sections was large enough to accommodate a proper entrance.


Based off the original design - to put an entrance in that tiny opening the structure would have 17' thick walls and they were 72' tall.

Yup... Back to the drawing board.


02-05-2013, 12:42 PM
I'm not an addict...swear.

Ok, so I rebuilt the whole structure to even up the lines and make the scale more accurate.


With this new design I could have the entrance in the small area created by the side-to-side wall and then open doors into either of the pentagonal rooms and then from there into the main chamber of the keep.



02-06-2013, 06:55 PM
I think perhaps you could try having the whole thing form one giant pentagon with the outer walls connecting the pentagons being slightly indented. Then have the central pentagon basically an open courtyard which would also act as a light well (so you can have big windows on the inside and small arrow loops on the outside. You could also crown the five corners with a corbeled-out turret too if you wanted.

02-14-2013, 11:54 PM

I just banged this together in sketchup really quick; I was curious to see how the geometry would work out, and it looks pretty sharp. This is a great idea, and I can't wait to see how your design and maps turn out.


02-15-2013, 03:16 AM
If you haven't given them a good look before, you should check out some images of star forts. They arose in response to the use of cannons in sieges. This particular configuration doesn't really have the same practical benefit as a star fort, but the aesthetic is similar.

I also think you might enjoy modeling a star fortress.

02-15-2013, 09:39 AM

I just banged this together in sketchup really quick; I was curious to see how the geometry would work out, and it looks pretty sharp. This is a great idea, and I can't wait to see how your design and maps turn out.



Yeah - that's basically where I was going with the design. The central part with the pointed roof and each surrounding pentagon with open areas looks awesome.

Thanks for the model!

02-16-2013, 03:42 PM
That does look good, I agree, but the problem remains of the issue of light. That big central hall isn't going to be getting much light at all even if it has fairly sizable windows, and if it has a ground floor then the rooms there will be getting none.

That changes of course if you have cheap, bright, practical lighting in your world but the lack of natural daylight is still going to be something of an issue.

02-16-2013, 04:19 PM
One of my original ideas was to turn the central pentagon into a partial sun well. That would provide natural lighting for the interior but not the exterior structures. Then it occurred to me to create sun wells in the center of each pentagonal structure - making them all "hollow" (perhaps with a centralized stair well) to allow natural light for each interior floor.


Like so.

Whatcha think?