Yup, 16 in all, and all of them count for the trophy you get for stepping foot in every area. Even if you don't hunt for them most can be found from quests either sending you there or starting there(late game you will have access to something that points you to all unstarted quests).
If anyone has a link to the English names of the locations in game I translate the hidden spots from the JP wiki, assuming someone else hasn't done so already.
It's not really hidden. Once you grab the errand and open your journal to read the errand it tells you there are people to the east. --- XBL: This Is A Trick / PSN: Komentra Steam: Komentra / Game Center (iOS): Komentra
Fun fact too, if you got the Wizard's Companion, these locations are listed in the book on the maps starting on page 312. --- I sometimes feel as though life is a curse that has been placed on the living. I envy the unborn at times.