The Fifth Edition version of Champions Universe first mentioned an intriguing-sounding location on CU Earth, called the Valley of Night. (The reference has since been reprinted in the 6E update to that book.) Few details about it were ever published, and there are no plans on the part of Hero Games to expand on them. However, I was inspired by that reference, and other elements from the official setting, to develop the Valley of Night for my own Champions campaign. Thinking that other gamers might find a use for them, I posted my (rather extensive) notes to the Hero Games discussion forums -- after first asking permission from Hero Games management -- where they seemed to be generally well received. The relevant discussion thread has long since passed into the obscurity of the forum archive; but this seemed to be an appropriate place to offer this material again for interested parties.
This download is a ZIP containing two files. The first is a PDF, a sort of "sourcebooklet," of most of the material I created for the Valley of Night. The second is a RTF document with additional info, mostly inspired by feedback from my fellow forumites. They describe the Valley's history, geography, unique environment and ecology, and society; more than a dozen NPCs and creatures; and numerous plots and plot seeds for using the Valley. Although inspired by official CU elements this material isn't closely tied to that setting; I designed it to be easily inserted into most superhero game campaigns. Although written with a supers game in mind, I also include notes on adapting the Valley to fantasy, pulp, modern adventure, or future sci-fi settings.
The material is somewhat bare-bones in format. It lacks character sheets for any of its original characters; instead I suggest modifications to the sheets of similar characters from Hero Games's Champions publications. The modifications are to the Fifth Edition write-ups for those characters, but should pose no significant problems to people using the 6E books they appear in. There are also no maps included -- map creation being a weakness of mine -- although all locations are described in substantial detail.
I hope you enjoy your exploration of the Valley of Night. Assuming you survive.