"Viper Mansion" (蛇骨館 , Jakotsukan (Snake Bone Museum)?) is a track composed by Yasunori Mitsuda for the game Chrono Cross. It is the fifteenth track from the first disc of the original soundtrack. The track plays before "Victory ~A Gift of Spring~" and directly after "Forest of Illusion". The song serves as the background theme for Viper Manor. In Japanese media, Viper Manor is called "Snake Bone Manor" or "Jakotsukan". The track sounds similar to Snakebone Mansion, a track played in the same location in Radical Dreamers: Nusumenai Hōseki. Employing sounds of mystique and sleuth, the song matches the atmosphere of infiltration, which is appropriate, since Serge, Kid, and another secretly gain access to the Manor.