Move towards the Background in Quarantine Zone

Description
In the level Quarantine Zone, after activating the Sputnik skull, if you escape the level by grenade jumping you can move towards the Library unstopped.

You must get out of the level in the area you start at (Where you encounter the Sentinels and the Enforcer). Activate the Sputnik skull and walk towards a low part of the cliff. Grenade jump up onto this cliff and you should be able to head towards the background of the Library.

Walk towards the Library in the background, and if you look behind you, you will notice the level becoming smaller and eventually disappearing. There is no way to get to the Library, but it makes for a nice view.