The Valve News Network—obviously, not a Valve-run news network, but rather a thorough YouTube channel dedicated to all things Valve—has released a new video, about Portal. The Unseen History of Portal delves deep into the making of the classic puzzler, presenting a bunch of unseen footage and little-known info in the process.

SEE Portal's origins as student project Narbacular Drop, WITNESS its evolution into a Valve property and into the Source engine, and BEHOLD what came after, i.e. cake. PC Gamer even gets a (very) brief mention—did our site really used to look like that?