Click on the map to see it bigger:
What tea is produced where?
Wen Shan: Baozhong
San Hsia: green tea (Bi luo chun, Lung Jing)
Yingge: pottery and ceramics
Emei, Beipu (and Miaoli): Oriental Beauty
Ming Jian: Si Ji Chun, Jade Oolong
the other locations are for high mountain luanze (qingxin) Oolong
Disclaimer: I placed the arrows using approximations and cross referencing with another paper map. It's not meant as a scientific work, but more to give a general idea of the major tea locations in Taiwan.
I also recommend you use Google Earth to visit these tea places.