It's a doorway open for a few minutes as many can get threw the door in that time can go for it. I see the thing as being regarded as a state treasure in the capital is a default place, you monarchs can decide different it's your kingdom, it was in the capital (for Nydewia in the castle of the Oasis) when you came to power, if you moved it more power to you.<br/><br/>Note only monarchs would know how to use the stones to open doorways, to anyone else they just look like really large(about the size of a mans fist) sized pieces of uncut pale sapphire with a hint of flickery light in the center.