The chests will always appear in the same place on or within the structure every time, unless the generation of another object interferes with its placement (such as when a tree 'grows' into a building). Some of the randomly generated builds will have Treasure Chests or Stud Chests included as part of the design when they are randomly generated. Many of the randomly generated structures in the world are also available as Blueprints which can be found in Treasure Chests or earned by completing Quests. These structures are generically referred to as 'Brick Builds.' Through the procedural random world generation system, these structures are added to each world, resulting in a more complex and interesting environment.
Throughout the world, in every Biome, there are structures that have been designed by the designers to enhance the atmosphere of the game.