Shadows of Midnight has published three adventure locations, and I recommend them because of their links to The Unexplained (Carnivore Games, http://carnivoregames.com/wp/).

"West Milford", although containing a few stat blocks for d20, is 97 pages of Unexplained weirdness: paranormal sites, UFOs, cryptozological sightings. It contains the creepiest photos taken by the author (a resident of the state of NJ) who did extensive research into the sites.

Not only is each site explained, but you get driving directions! The author also provides non-paranormal explanations of all sites, includes a mini-campaign that connects them in a bloody modern-day Cult war (Slasher-film style), character templates (for d20 but easily portable) and advice for using the entries for a variety of other uses (police investigation, UFO). Also includes are modern-day horrors ("new elementals"), the Radon monster and the Lead monster (spontaneously oozing out of the radiation-infected local or the lead-poisoned homes).

Note that the primary focus for the mini-campaign focues on the incredibly disturbing Cult slayings that focus one of the claims of the area (Demon Alley -- only one of the backgrounds, but a slaughter-house mess) but do include the ghost-hauntings as well.