Castlevania: Symphony of the Night

I would just direct you to this board
http://www.gamefaqs.com/boards/genmessage.php?board=937723&topic=44976002
Very detailed maps and help for this specific subject. Usually since people are only missing one or two rooms it's quite difficult for people to tell which exactly those are, however if you can post a pic. of your map on that board people can usually tell you exactly where you still need to go.

What I ended up doing was printing a map of the game (which is available at many locations online, including GameFAQs) and marking off all of the rooms with a Sharpie marker until I found the ones that I was missing. If you have the patience, it's a foolproof way of finding the missing areas. It's a good bet that the rooms you are missing need to either be smashed open with an axe (ceiling) or cracked open with holy water (floor). Those were what was keeping me from getting it.