This mail box marker location is incorrect, there is no mail box in the grounds of the Maritime Museum.
There is a mail box located on Dock Street, in front of the Griffith Film School, almost directly south of where this marker is currently located. This marker may belong there instead.

flower bed with trees

Last time I came here I think this area was complete with a outdoor lounge area and a building.

Unable to answer "What are the opening hours of My Sweetopia?" for osm.org/node/599899635 via StreetComplete 6.1:

Now 'Lost Bean', coffee shop

Unable to answer "What are the opening hours of Ramen?" for osm.org/node/5114720557 via StreetComplete 6.1:

now BMT, a restaurant of some sort

Unable to answer "What are the opening hours of "Ramen"?" for osm.org/node/5114720557 via StreetComplete 3.0:

this might be closed, as I hasn't been opened when I've been here twice.

Attached photo(s):

Unable to answer "What are the opening hours of Mr Fitz's?" for osm.org/node/5114720558 via StreetComplete 6.1:

no longer here

Unable to answer "What are the opening hours of Doughnut Time?" for osm.org/node/5114720556 via StreetComplete 6.1:

no longer here

Unable to answer "What are the collection times of this postbox?" for osm.org/node/319154622 via StreetComplete 6.1:

no post box here

Road does not exist

via StreetComplete 7.1