From Video Game Music Preservation Foundation Wiki
Clockwork is a song that first appeared in Akumajou Densetsu (FC). It played while you were inside the Clock Tower and it has since been remixed in many Castlevania games. It has also been considered to be the theme of Grant Danasty.
Akumajou Densetsu (FC)
Castlevania III: Dracula's Curse (NES)
Castlevania: Circle of the Moon (GBA)
Castlevania: Judgment (WII)