Board Thread:Dragon City Gameplay Questions & Answers/@comment-11825618-20130815144938/@comment-10760902-20130815151958

You only completed the first part of the Dungeon Quest, so you only got the Dungeon Base. The Dungeon Base is something like an island, it provide room for placing Dugeon Habitat (which can only place on Dugeon Base). So basicly, without Dugeon Habitat, Dugeon Base is just an island with no function. It can't be moved or sold because this item is special configured to permenantly stay at that position.

Why would you want to move or sell it? I know it's useless but it doesn't cost you anything.