I don't see the connection between the garden and the opera house. The image is severely tilted and the composition is unclear, what is your subject ? the bridge or the opera house. It feels like the image is split in two. Sorry, 3
It's a bit skewed clockwise, but a nice feel about it - and weirdly refreshing against so much greenery and macros! Nice idea - although the title could be 'Cobbled Garden'... [7]
First, the photo. I love the lense flare at the top of the Sydney Opera House and the exposure. The lighting on the bridge and the city lights in the background came out perfectly. The Harbour bridge makes the image look a bit crooked though. From the title I know including this amount of concrete was intentional but less of it, more of the opera house and less of the bridge would probably balance it better.
Second, this is a bit of a stretch for the challenge. There are several good locations in Sydney that may have proved a better choice.