I often wonder why, how and who could/would come up with a name like "Castlevania" ??? I often find that asian titles translated into English sound ... odd.
Yeah, it's completely nonsensical in a way.

The original title – in Japanese – makes more sense: Akumajo Dracula.
This is just one in a list of many games that go by the name of Castlevania actually. Here's the wikipedia link if you'd like to know more:
http://en.wikipedia.org/wiki/Castlevania