From 1832, this complex was used as a quarantine station for immigrants. They had to spend here some time before they were let into the country. Now it has been redeveloped into an urban complex which is home to a hotel and a restaurant "Q Station". You can join various ghost and paranormal tours of the complex.
To get here, you can take a ferry departing from Circular Quay.
Wikipedia https://en.wikipedia.org/wiki/North_Head_Quarantine_Station
Official Website http://www.quarantinestation.com.au/
Address Sydney 2095, Australia
Coordinates -33°48'53.28" N 151°17'17.16" E