Palace lawyer Anne Marie Corominas knows exactly where to find every ancient map of the Philippines and Asia that she has collected more than 20 years in her Makati City home.

Whether these maps are kept in acid-free binders, picture frames or tube containers usually used by architects to store their works, Corominas, who has never made an inventory of her collection, can find them in a flash.

And as typical of serious map or even art collectors, she also knows every bit of the details in each of her original maps—their design elements and all—but more important, the story that they tell of the history of the Philippines and Asia.

Who would have thought that one day her treasured map collection would be handy for the government in its territorial dispute with China in the West Philippine Sea?