A Chaitya or Chorten usually contain within them some relics. These ancient icons of Buddhist art and architecture are found all over the Himalaya. Each level is representative of some element.
The square foundation symbolises the earth. Following that, the dome represents water while the thirteen tapering steps of enlightenment symbolises the fire element. Above the fire is a parasol which is the wind. This is topped in the void or the ethereal sphere represented by the twin symbol uniting sun and moon. This is the emblem of the Twin-unity of the Absolute Truth beyond normal comprehension and the Relative Truth that we know in this world.
Image: A Chaitya - Chorten set amidst tea bushes somewhere in Ilam, Nepal.