Castle Viiten is made from petrified wood, and though it may look like carved wood, the trunks that make up the towers and over castle itself are just as tough as any stone. Yet, because it is made out of the petrified wood and is solid pieces of it, it just looks like giant harden tree trunks. The run carved into the base allows the castle, when it is activated, to meld into the shadows and basically become invisible if the time of day is right. If any shadow touches the rune lines in anyway the castle will virtually disappear to the naked eye and can only be found by touch.