Brisbane and the Brisbane River is divided by Bridges. At one end is the Story Bridge, with Victoria Bridge in the middle and The William Jolly bridge at the other end. This is basically the city of Brisbane and you can walk across one bridge, then along Southbank, walk back over another bridge and return to where you started from. Its a great way to see Brisbane, by walking it.
Eagle Pier is the most active Jetty with a great selection of restaurants, the Riverboats that do lunches and river tours from here, and access to the many Hotels and accommodation high rise buildings that line the shore. This time I stayed at Mantra on the Quay with a great view of the river ahead and the buildings below.
You can walk to West End and New farm in one direction, and to the Casino in the other direction. Both walks are about 4 kilometres each along the water, and when you get tired, just hop on the free City hopper, , the little red ferry, or one of the big River Cats to return you to your starting point or end. Or, If you are fit and game, try the yellow scooters that are parked along the track and scooter your way from one end of Brisbane to the other.
From Eagle Pier, you can walk inland and follow the main street back to the Casino and then walk across Victoria Bridge to Southbank. The city has some beautiful buildings and churches and a lot of history. The Cathedrals are usually open and you are free to wander in and view the beautiful architecture and stained glass windows.