When you would rather compare geographic locations in steven universe than actually watch the show...

Beach city is in the northeastern united states around maryland.
The first kindergarten seems to be in georgia from what I estimate.
The second kindergarten is located in the western united states somewhere along the colorado river between arizona and california.
There are other structures built in the ocean where russia SHOULD be on a map
A number of structures in the atlantic ocean off the coast of the united states.
One near Argentina which I assume is a mayan structure.
one in china, several others in asia and europe.
two in the UK, one in spain.

Here's the map. Sorry if my geography is off.
And on top of that, the map is extremely misshapen compared to the real world map.