Mark Farmer | SD_Doomsday and CP_Foundry Secrets [Team Fortress 2] @rct2guy | Uploaded 12 years ago | Updated 2 hours ago
You can easily find these yourself by simply noclip-ing to them like I did in the video.
These have already been found and documented (see http://wiki.teamfortress.com/wiki/Doomsday#Trivia ), but here's video proof, and a closer look at the photos/map. (Sorry I had a hard time focusing on each of them!)
EDIT: It has come to light that these (along with many other materials) are all hints leading up to Team Fortress 2's Mann vs. Machine update!
You can easily find these yourself by simply noclip-ing to them like I did in the video.
These have already been found and documented (see http://wiki.teamfortress.com/wiki/Doomsday#Trivia ), but here's video proof, and a closer look at the photos/map. (Sorry I had a hard time focusing on each of them!)
EDIT: It has come to light that these (along with many other materials) are all hints leading up to Team Fortress 2's Mann vs. Machine update!