In terms of geology, much of Mandurah lies on the dune systems which dominate South Western WA's coastline, progressively grading towards the Swan Coastal Plain as one travels inland. The area has infertile soils due to the dunes being rather sandy, having poor water retention qualities. Limestone outcrops are found to the north of the city especially along the Mandurah railway line. Mandurah is the closest city to Yalgorup National Park which is home to modern thrombolites as well as an array of flora and fauna.
