This is a very Folklorish title, with a great overview of the setting historically with details on Geography, Locales and a great section on Legends and Customs. If you got the Cthulhu Britannica: Folklore, and enjoyed it you'll want to get this. With 3 quality investigations plus scenario suggestions you cant go wrong.
Think: the mystery of Holy Grail, Wicker Man, King Arthur, witches, Hammer Horror rural setting & deep ones and you're on the right trail. Both this and the Folklore supplement allow you to do something a little different with CoC. Worth the read alone. 5 stars