Sunset at Port Willunga jetty on a cloudy winter's evening in Adelaide's southern suburbs. Port Willunga Jetty south of Adelaide was first built in 1853 to allow the export of grain. It was one of the busiest ports in South Australia. Its hey day didn't last and by the 1870's grain exports had declined sharply. After being used for the export of slate from Willunga for several years, the jetty was in a state of disrepair by the early twentieth century.