Darling Harbour is one of the happening place in Sydney City, where you can eat & drink, shop, explore and do many more. Every weekend on Saturday, there is a spectacular fireworks on Darling Harbour which makes the places very crowded. Here you can find a lot of restaurants and bars like Hard rock Cafe, Crinitis, Cafe del Mar Sydney, Pontoon Bar etc.There is a huge park with kids playing areas along with open air cinemas(occasionally).
Also for activities, there is Ferries wheel along side time zone gaming area. There is a also a reconstruction going on for the biggest iMax threatre in the world which is expected to be completed by Late 2020.
This place is a highly recommended place if you happen to visit Sydney.