Just had a look for a post of Descent's, can't find it. It was a comment that the dragons wouldn't be able to fly because of physics, and that the ice wall is, again, too big and physics get in the way.
So, here's some thoughts on making it all sciencey. I think we can all happily say it's a different planet. What if the people, that look remarkably like humans of Earth, are in fact like a millimetre tall? That right there would fix some physics complaints.
Another idea, the water is different on that planet than it is on Earth, though what that difference would be I couldn't say.
Dragons. Now, providing that the people of that planet aren't in fact a millimetre tall, making the most ginormous dragon you could ever dream of about an inch from tail to snout, what about this:
Let's say the bones are hollow, like a bird. It has unique organs that are specifically used to hold gas, internal bladders. Maybe the lungs but I don't know how that would work (any biologists want to chip in?). Why not fill the internal bladders (or whatever) with hydrogen and methane? Both not only lighter than air and giving a lift to get off the ground, but also combustible which of course directly relates to the ability to breath fire. Now, let's keep in mind that dragon lairs are usually rocky. Mountains, caves. As well as being a good defence and perfect places for a flying creature, what if dragons choose places that have platinum? It would fit with why dragons inhabit these places. Crunching and swallowing the platinum found in the rocks. Perfect catalyst for igniting the gas reverses to produce fire. Platinum, hydrogen and oxygen. Boom. The gas would also give the lift to allow dragons to stalk prey silently, or near enough.
Now obviously the internal bladders would double up as both the means to fly and breath fire, so the more fire it used the less able to fly. It would actually make sense if we're to consider dragon slayers. If the gas reserves are low flying away isn't an option and fire breathing isn't much of a worry.
So yeah, just a random thought. The bacteria inside the dragon's gut produces hydrogen. The hydrogen produced in the gut is then transferred into the internal bladders, and dragons instinctively establish territory in areas which have rocks rich in platinum.
Topic: Game of Thrones