That has been speculated about for a long time. Was it there when the game started? IF not my first account didnt start till 2014 i think it was there. Some think its the Coronation Building where our King/Queendom Avatars will be declared the Ruler and the Baron is sent packing. People have speculated what is inside the Dome.. It looks like to me royal type things. A scepter/Robe/Jeweled Crown etc.. Is it a EndGame thing? I guess one day we will find out.