I have been living in Sydney for a few years now and there are areas of the city that I know very well. But there are many others that I just don't know, because I've never been there or because I've only been passing through. On the other hand, in a big city like Sydney, it is difficult to get familiar with all the various neighbourhoods unless you do nothing more than explore every week!
Likewise, there are many Sydney attractions that I haven't visited yet, you want it because I'm waiting for the right opportunity to do it, you want it because it's not at the top of my priority list, you want it because I prefer to spend time out of town or due to lockdowns and other restrictions.
Then there are some places, like museums, I’d never grow tired to visit and I can consider myself to be a guide there.
Unfortunately, due to the new restrictions for Covid-19, most museums are now closed to visitors and I can’t wait to return to visit them again.
Here are a few you can perhaps find only in this city:

The Powerhouse Museum ------------------------------------------------------------

Together with the Sydney Observatory, the Powerhouse Museum is part of the Museum of Applied Arts & Sciences but I had never visited this part of the structure.
This museum is often described as a science museum, but in reality, the Powerhouse is not just that, as it offers exhibits that include pieces relating to art, science, communications, transportation, furniture, technology, space and motors. In addition to the permanent ones, the museum often hosts really nice temporary exhibitions too. It also contains a former power station for electric trams that dates back to the beginning of the 20th century.
I had been to this place before but it’s my absolute favourite because it teaches you a lot about how trains and technology work and it’s great with kids too.

The Hyde Park Barracks Museum ----------------------------------------------------

This UNESCO heritage museum is one of the most significant convict sites in the world. A meeting and exchange place for tens of thousands of prisoners, it played a central role in what was the largest and longest prisoner transport system in history. This museum tells the story of the site, from the trees during the transportation of prisoners to its role as a lodging for immigrant women in the second half of the 1800s, to its recent past as a courthouse to the present as a historic site and museum.
It is indeed a splendid museum to discover the rich history of Sydney and Australia as a new country.

The Customs House --------------------------------------------------------------------

It is so called because, since 1845, the Customs Office operated here, housing the offices of government officials who processed the paperwork for the import and export of goods to and from the country. This building is one of Sydney's historical icons and is now a public space where you can reconnect with the city's past but with an eye to the future. The best piece in the Customs House is the 3D model of the city centre: a great way to orient yourself if you are on your first visit to the city.
The building also houses the Sydney City Council library and public space where you can study or read in peace, as well as various events and temporary exhibitions in normal historical times.

The Rocks Discovery Museum -------------------------------------------------------

This completely free museum in the heart of The Rocks area, in a sandstone warehouse dating back to 1850 and the building itself tells the history of The Rocks from pre-colonial Sydney to the present. The museum presents a unique collection of images and artifacts found in the area, presented in a highly interactive and fun way. The Discovery Museum was created in close collaboration with the Aboriginal people of the area and is truly one of the best places to find out more about Australia's first inhabitants.