These are Cabbage Tree palms - livistona australis. When Sydney was settled by Europeans in January 1788, there were healthy stands of CTP around the area. However, within a few short months, there were very few within 10 miles of Sydney Cove. The fanned leaves were sought after for thatching daub and wattle huts.
The City of Sydney is replanting these palms at a great rate of knots. They are not my favourite. I gather the inner part of the fan develops a fruit in the shape of a cabbage. It also has long brushes of white flowers.