Creating 4th edition D&D dungeons

If you look at the name of the game Dungeons & Dragons and compare it with the reality of pen & paper roleplaying, it is obvious that the Dungeons part is far more frequent than the Dragons part. Over an average full campaign you will have many dungeons, but only few dragons. One reason for that is that "dungeons" is a far more open term than "dragons", there can be millions of different dungeons. If you need a dragon, you just take one from the Monster Manual; if you need a dungeon it

World of Warkraft...