I have built a huge Citadel in Space Engineers, my own Aperture science. It is 775m tall, 75 blocks each side. Science rooms beyond you're imagination, both small and huge. About 550m up in the tower, there is the main computer.. a colossal Aperture science brain. But can you find her?... The Citadel itself gives a ambient and a eerie feeling at the same time while you're in it. You can even find rooms that leads to outside of the tower, balcony or other ways maybe, who knows.. find out. While you're testing my Citadel (if you want), Play some ambient sounds on youtube for perfect feeling. Maybe this video or Half life 2 Citadel sound. Cheers from Sweden.