If you just try guessing co-ordinates yourself, you might end up in the sea, or
some other "forbidden" location, and the program will crash.
I don't know about Largest Earth, but with Giant Earth there is a very extensive
list of locations in a file named CityMap.xml in the same directory as Map.xml.
You can look up the co-ordinates for the location of the city you want in that
file and then replace the coordinates in the Map.xml file.
For example, if you want to start in Adelaide, look in CityMap.xml. It shows:
<Replace MapName="GiantEarth" X="97" Y="10" CityLocaleName="LOC_CITY_NAME_ADELAIDE" Area="0" />
which is the location of Sydney.
In Map.xml you will see the line:
<Replace MapName="GiantEarth" Civilization="CIVILIZATION_AUSTRALIA" X="92" Y="24" />
Replace the X and Y ordinates so it now looks like:
<Replace MapName="GiantEarth" Civilization="CIVILIZATION_AUSTRALIA" X="97" Y="10" />
When you restart Civ, your settler will appear in Adelaide, you lucky, lucky bastard!
Drop in, but bring cake.
You might not be getting Sydney to appear as a city-state when you choose only
31 city states. I always choose 60. Also, it might be that Sydney doesn't appear
because others have been (randomly) chosen by the program.
I noticed that using the Closer Cities option in Gedemon's Add-Ons mod changed
the behaviour of many things in the Giant Map, for the better!
Firstly, it made Giant's Causeway, Eyjafjallajokull and Lysefjord wonders appear.
They never did when I used the standard separation of 3 hexes.
Secondly, a whole raft of city-states came up that didn't before.
For example, Antananarivo was never created because, I presume, it was too
close to the Tsingy wonder on Madagascar. Auckland appeared for the first time
as well. (That's a great one to get, and to keep other civs from finding for as
long as you can, btw.)
I also use the Remove Close City-States mod in Add-Ons, which removes Lisbon,
Brussels and Geneva, so you don't actually end up with 60 CS in total.