First i took and cut the floor then make it as celling.Second,i cut the pillar and make it two sided.third,cut the floor again and make it a down floor for dome.Fourth,cut source 1 and paste as door.Fifth,flatten the image,paste into source 2.Finally,i use shadow and highlight,colour balance,HDR tonning,level,Brightness and contrast for adjustment

Used only source image, and adjustments/filters within CS4.

Just wanted to do something realistic.