Australia—Three Dimensionality
"Scratching the Surface" portrait (2013) of labour leader and environmental activist Jack Mundey by Portugese street artist Alexandre Farto (Vhils) on a stairway at The Rocks in Sydney.  It is interesting to watch people walk through the portrait and the artist's technique is very distinctive.
This ornamentation on a building in Sydney has multiple layers, highlighted by use of a different material in the top layer.