Many of our dragon legends and movies involve the great beasts guarding massive piles of treasure, usually gold or a combination of gold and other precious metal objects. They are almost always shown lying on top of it,or burrowing into it as we and other animals would treat a warm, cozy bed. Dragons cannot spend, wear or alter their prizes; of what use are they?
Some stories tell of “dragon sickness” and dragons being evil and greedy and simply desiring to have what others cannot; I think these are all very viable reasons, but one book I used to check out of the library as a child had, for me, what was the most sensible reason of all. I cannot remember the name of the book; if I could I would love to find it online. But on one page,it simply explained why dragons lie on gold: A dragon’s body is corrosive. Whether because of sheer evil,or simply the scientific processes that culminate to make a dragon breathe fire, a dragon seeps and sweats corrosive fluids, and it is always in search of something to lie on that will not soon be eaten away by its body. Precious metals seem to fit the bill, although probably other less exciting metals might be chosen. However, gold is most likely the champion metal simply for its beauty–a tale telling of a knight who has come to reclaim a dragon’s hoard of iron might not prove as exciting!