Architecture and the elements are intimately interconnected. It is estimated that around 50% of the world’s population lives or works in earth buildings, constructed mainly of dirt (clay, gravel, sand, silt, soil, loam and mud). Stone, also of the earth, has been used to great effect by civilisations like the Tiahuanacu and Inka, as well as in buildings in Europe and their colonies. Iconic buildings like the Flame Towers in Baku, Azerbaijan pay homage to the elements. And ancient practices such as Feng Shui from China and Vastu Shastra from India use the elements to assist with the placement of buildings in a landscape, on a site and their internal design.