How to make one
The dirt can just be dyed dirt from the Sandara Desert, the dragons won't notice any difference. The flying rock in the normal one must be enchanted with Aeromancy to keep it in the air and a lot of Erudine Crystals are required: the more, the merrier.
The normal one represents a random location in the Crystal Highlands along with a floating rock found more commonly in the Verulean Highlands. The large one represents a rare rock formation found there where Lightning Dragons socialize and hold staring contests. The giant one represents the biggest Erudine Crystal found in the whole area, along with even rarer rock formations, where Lightning Dragons do all activities from the other rare rock formation AND even more. The giant crystal is built up of other crystals instead of mining the actual crystal.