This tutorial is for an interior to a fort, I made a throne room just to show the type of stuff you can do with the interior tileset.
This is a short, and basic tutorial. Sorry if it's really short, and not too in depth. I'm in a bit of a hurry, and felt bad for making the requestee wait for so long. I'll probably edit it a bit later.
Step One:Make a new map, fill the first layer with the floor tile.
Step Two:Add the roof / wall tiles. Using these tiles. Like in the exterior, don't forget about adding the corners.
It should look something like this.
Step Three:Add some stuff to fill in the space, and make it look more realistic. Don't forget to add some events, you'll need a king, queen, and some soldiers.
This is what it will look like ingame.