This is area where you fight Ridley in either Metroid, Zero Mission or Super Metroid...anyway, its pretty large and detailed.
Don`t ask where did this platform came from - i have no idea. Includes moving lava (there is not much lava shown because of the angle) and Ridley-X`s theme as BGM.
Preview (zoomed out):
Download link: http://www.4shared.com/rar/sraAGbrvba/Ridleys_Lair.html
Is that just a stage or hi-res stage? If former, then i will change it to "Stage". Next one is a place you visit before facing life-energy-eating Metroids...