The rock paintings and engravings of Sydney reflect the artistic inclinations of the Aboriginal population before the Europeans came to settle in this historical city. Rock engravings and paintings show the close relation the Aborigines had with the sea. The engravings and paintings were mostly about creatures related to the sea such as whales and sharks and other fish. Gwion Gwion is a form of rock painting seen in caves, which is believed to belong to a culture that existed long before the Aboriginal culture as it is known today.
In addition to rock painting, engraving, carving and sculpture, indigenous art also includes painting on leaves, carving on wood, sand painting and artworks on cloths. Body painting is an indigenous art which covers the body with intricate, exquisite patterns. The same art is seen in a varied form in bark painting. Paintings were done traditionally on bark walls and ceilings.
Stone arrangements of large and small stones embedded into the soil are unique to Aboriginal Australian art as well as weaving, jewellery making and crafts made from various forms of fibres.
Other forms of art such as dancing and singing were interlaced with the daily routines of Aboriginal life. The Aboriginal people sang while they performed their daily chores. Aboriginal fishing women sang all day paddling in rhythm with their music...

Throughout the twentieth century, artists in the vanguard have repeatedly challenged convention by exploring new avenues of expression and seeking alternative forms to embody new ideas. In the early years of the century, the so-called fauve artists ("wild beasts") in France, led by Henri Matisse, experimented with vivid, highly saturated colors and bold brushwork to evoke intense emotional responses. Later, artists such as the Russian Wassily Kandinsky carried these experiments further, creating abbreviated shapes that, however abstract, were meant to stand for specific concepts or forms.
Pablo Picasso and Georges Braque were responsible for one of the most radical innovations of the century. In their cubist paintings, these artists defied the long-held notion that painting provided a "window" into deep fictional space. Instead, they fractured forms and space into shifting planes and reduced their palette to a few muted tones. Yet Picasso never favored absolute abstraction as did Piet Mondrian, who eventually eliminated any reference to the natural world from the rigorous compositions of straight lines and primary colors that he intended as the expression of an ideal and universal order...

Extraordinary usage for lots of coins - without glue or scaffolding.  Just very carefully put one coin on another. A few hours a day months of practice and maybe you will be able to do something similar to these structures? Amazing physical law showed in a different way...