Only one. Deathwings lair:Originally Posted by Somnio
http://www.wowwiki.com/Imageraenor_map.jpg
Look east of the dark portal.
edit: i was just reading up about deathwing and found this:
Grim Batol with deathwing being the final boss? yes please!# Grim Batol; which "...has the distinction of being the last place that the evil black dragon Deathwing was spotted. I do not believe that he is dead - perhaps the red dragons have taken him captive?".[9]