In this page, I will post everything related to background information in the Pikmin series (rests from the human civilization, for example). I will try to classify them (decorations, machines, and so...)
Made by humans
A bell. It is similar to the Danger Chime in Pikmin 2.
A glove which resembles the Five-man Napsack.
A tyre. Tyres appear in Pikmin 3 and are found in the following areas : Stagnant Sea, Sandpit Kingdom.
A montage showing the different screwdrivers found in Pikmin 3. The green and red screwdrivers can be found in Clockwork Chasm, while the blue and yellow screwdrivers can be found in the Corroded Maze.
A montage showing the control valves appearing in Pikmin 3. The white valve appears in the Corroded Maze, whereas the others appear in the Clockwork Chasm.
A gutter in The Rustyard. In Pikmin 2, it's possible to find gutters as well (in the Shower Room, for example)