Get up early and do an epic round the river 10km walk or run. Starting at South Perth you could begin with a takeaway coffee at one of the many cafés near the jetty to fire you up... (or wait till a little later on). Go left and follow the trail it will take you all the way from South Perth esplanade right over narrows bridge, down around the water front to Elizabeth Quay. There is plenty of sights to see here and more coffee options, you could walk over the new bridge and carry on up the track to Langley park. The trail continues on in a straight line then takes you past the soon to be Ku De Ta where you cross the first bridge over to Herisson island. Keep going and turn right after the second bridge and your about half way… The trail is a lovely walk along the river and you will make you way past little lakes and then the boatshed café. Keep walking and you will get back to where you started. Its such a nice walk and could take anywhere from an hour to two hours depending how fast you want to go. I would highly recommend doing this on a nice morning.