It's a site that gives an overly serious, scientific analysis of mythological, paranormal shizzle. Think of it as a version of creepypasta with really strict quality controls in place. Scp-173 is the first I read, makes a nice introduction.
http://scp-wiki.wikidot.com/scp-914 is prolly my fave tho.
note; there are some really stupid ones mixed in there, and make sure to read the tags if you think its retarded, as its probably a joke one