Level 7 is an infinite space in complete darkness, filled with a layered maze of railingless catwalks, pipes, and infinitely tall cooling towers. The temperature hovers around 20 degrees Fahrenheit (-7 degrees Celsius), so warm clothing is advised.  Level 7 does not merely lack light, there is no such thing as light in Level 7, any light source taken into Level 7 will cease to emit light upon entering.