Isle of lendore
The fortress is very well defended, mostly crewed by kobbolds and camouflage elves. Aerial knights flying bats, giant owls, hippogriff, etc are the mainstay of the complement.
A mountain at the crest of the pass holds a Lamia who has gathered other flying creatures to take over the northern side of the pass.
It appears the remaining piece of the gold dragon statue that Pyfiravin had been searching for may be in the mountain.