Mr. X's Castle, known as the X Foundation Headquarters (エックス財団本部ビル Ekkusu Zaidan Honbu Biru?) in Japan, is the fortress used by "Mr. X" in Mega Man 6. Mr. X's Castle consists of four parts, called Mr. X Stages (Mr.Xステージ Misutā Ekkusu Sutēji?). The final part of the fortress ends with a battle between Mega Man and Mr. X. __TOC__