Spyro the Dragon

Explore everywhere! Here's the route to a dragon that everyone can't seem to find:

Charge down, into the hall. Take the far metal door (the one leading
back outside) but don't fall for the ramp, it doesn't lead anywhere.
Instead, hug the wall and go left, and jump onto the area. Remember the
ramp I told you to remember? You'd better! Charge up it, and now glide
to the platform on the side. Go inside (you might need a whirlwind, I
can't remember) and go inside. Rescue the dragon, and now things get
tricky. Jump up all the steps, but EXTREMELY quickly, as the piles of
armor will animate into Tin Knights. If you're fast enough, kill the
wizard, and blast open the wooden door. The special fairy behind gives
you permanent super fire as long as you're in Haunted Towers. Kill all
the Tin Knights, and go back outside and destroy the iron box. Then,
fall down the hole back into the main hall. Take the passage behind the
other door, and from here just glide to the fortress and clear out all
the enemies. The last wizard guards the exit, so take it.

Yeah, I just copied and pasted it from an FAQ but at least it answers your question. Well, sort of... This path should get you a dragon and some more gems but the rest are up to you to get because I don't know where you haven't been.