To be more precise, about it's size. According to Nell, from the point they broke in, it would take 3 days to walk to the door. So I did some calculations, and the place would be really fucking huge ! 3 days to the closest door. We can assume Las Noches is circular, so in the most extreme case, the door is on the opposite side from where they are now ( see crafty picture ). 3 days = 72 hours. So you walk around Las Noches 2 x 72 hours = 144 hours This is the circumference. Now the formula for the circumference is 2xPixradius so this is 144 = 2 x Pi(3.14) x radius From this you can figure the radius out : 144/ ( 2 x 3.14 ) = 23 hours = radius Now I'm getting to the point. Hime is most probably at the center of Las Noches, in those towers. So the radius is the point from the center to the outside border of the circle ( Las Noches ), you should all know this ( elementary maths ). The radius is 23 hours. So it is gonna take them 23 hours to get to Hime. Note that the placement of the door at the opposite side is the most opportunistic placement. If the door is not on the opposite side, but closer, then it is gonna take them even longer !