Treasure Chests are sold as Decorations for 10 KC and indeed can be placed and used as decorations in your Kingdom as they are quite beautiful. They are designed to be opened, however, as they contain unique items that cannot be obtained in any other manner.
Among the items one can obtain in a Treasure Chest are:
Mermaid Fountain:
Category: Decoration
Can be activated as a fountain but does not produce Mana
Barn Owl
Category: Creature
Sell for 500 Mana
Portal Winds
Category: Artifact
Yields: 500 Mana
Empower for 100 Mana
Sell for 400 Mana
Tower Ruins
Category: Building or Decoration
Sell for 350 Mana
Tree of the Fallen
Category: Decoration
Can be activated like a lamp but does not produce Mana
Sell for 650G
