Touring Sydney's Best Sites on Public Transport with a Few Dollars

In Sydney, I used my VISA credit card as a ticket for buses, light rails, subways, and ferries. American Express, Mastercard, and Opal are equally valid payment options too.
For short-term or first-time visitors with those credit cards, I highly recommend spending 3-4 hours to explore the best spots in Sydney using public transport with just a few dollars.
1. Walk through Royal Botanic Garden Sydney.
2. Proceed to the Sydney Opera House.
3. Take a ferry from Circular Quay and go to "Milsons Point Wharf (Luna Park)" and "City Lookout from Milsons Point" for the best view of the Opera House.
4. Ride trains from Milsons Point Station to Central Station. Pass through Sydney Harbour Bridge.
5. From Central Station, hop on the light rail to Downtown Sydney.

[@robertthomson1587]

Very informative. Thank you.

[@petercharles8306]

Pittwater inlet is Sydney's jewel

[@staryoshi06]

Mastercard and American Express are also supported. Cards must support preauth so you can't use Maestro.
If you don't have one of these, you can get an Opal card at most convenience stores and load it with cash at most train stations, interchanges and ferry wharves.