English artist Richard Long's White Water Falls (2012) in Sydney is really worth a look. It's a fantastic surprise in the stairwell atrium of the Kinghorn Cancer Centre in Darlinghurst (370 Victoria Street). It's not a place we'd normally go to view art, but totally rewarding - I was so pleased to be told about it when I was close by!
Long has made the extraordinary wall work work by mixing a relatively small proportion of powdered china clay with a much larger proportion of water. He's adjusted the massive work at each of eight levels with hand marks where he could reach the wall; so each level is unique, but all are made the same way. I understand the architect invited the artist so there's a sense of collaboration from the outset, but also, as the artist notes on site and online, 'I make part of the work and the forces of nature - gravity and chance - make the rest.' My inadequate image is attached, but you can also visit tkcc.org.au/richard-long-artwork/