They spawn all along the sides if Mt Olympus, the mountain at 50, 40

there are also the eggs?

Yes, there are a couple of spots along the side, i found like four of them.

thx, found it

hello
i search red gems, for rock drake saddle.
Did you find it anywhere?

You can mine red gems from purple crystals in caves. I found some in the cave in the western islands right around the snowy island (not sure which name the cave is called though).