9. BioShock Infinite's Axed Mountain Observatory
The list of cut content and unused concepts for 2013's BioShock Infinite is, well, infinite, and includes axed levels, buildings, and even some abandoned art styles.
A lot of this content was never actually built within the game, and as such, it only exists online in the form of concept art or early screenshots. But some areas were constructed and added into the mix, only to be left out of the playable path of the final product - just like the mountain observatory was.
This observatory can still be accessed by players who wish to find it, however. Glitching through the boundaries in the Sea Of Doors will lead you to a rough version of this area, complete with snowy cliffs, a stone staircase, and a wooden bridge connecting two peaks.
There isn't much else to do here other than look around a simplistic and unfinished series of mountains, with an empty observatory in the middle. Still, it's a cool little secret for fans who wish to take an even deeper dive into the amazing world that Infinite created.