When drawing interiors, wheter it's a house, a castle, a dungeon or a ship (even a spaceship) it's always good to be able to draw some walls. This tutorial goes trough a few different ways to draw walls and castles.
If you are going to draw the traditional square rooms the tool of choise is the rectangle (). By settings the grid units to 1 under File->Properties in the "Grind & Snap" tab and turning on grid snap () you get your rectangles to line up nicely with the grid lines. For bent corridors you can use the polyline tool (). We can then quickly create a simple dungeon map.
By setting the grid, background and fill colours as well as setting the grid level we can get quite a nice map using this method.
With a few added symbols we quickly get a dungeon map.