With heavy escort, Anton Undain his grand-grandfather used to use these woods as his hunting ground for a while. That is when it got named Undain woods. Most inhabitants of these woods (mostly Nymph ) resent this name though and might use the older nymph name of "Spiti" (which means "home" in the original nymph language).
Their are some differences between Undain woods and the other forests of Midgard. First of all Nymph and Slemmering are more common in Undain woods. Also the forest is a in the middle of the spectrum of harshness. All Midgardian forests are harsh, but Undain woods is not as harsh as Long Ear Forest but more harsh than Damp Forest .