@semerl If it needs to be big enough to accommodate two cities we are.

@Silverlight
We're not talking about a mansion-sized island.

@BlueBlur64: It's been fixed now.

Where's the bottom of the last few letters? They just cut off.

I don't mean this exact map (the island is too small imo). It was likely dropped early before sprite art commenced.
The zone order would've been like, Green Hill, Bridge, Marble, Jungle, Spring Yard, Labyrinth, Starlight, Scrap Brain, Sky Base.

The city in SY and SL seems to be built into the mountains. It's still visible after exiting the Labyrinth caverns. But like i said, this island rendition is too small and cramped to accommodate all that. What bugs me is that Scrap Brain is built on top of the highest peak here making it look more like a fortress. In the 16-bit (and even in the 8-bit) it's clearly a city on a level plain on the other side of the island.

@Silverlight If it was originally planned to be in the original Mega Drive version, where would Marble, Spring Yard and Star Light be on the map?

Also the 8-bit versions were going to have Marble Zone in the game but the only thing that remained were a few sprites and the song. So this map was made after that zone got axed. From what I read (can't find any sources so this is probably faulty memory here) that the 8-bit versions were going to follow the Genesis version more closely until it became its own game. Not the only Sega game that this happened during this time (the Master System version of Castle of Illusion, the Mega Drive versions of ESWAT and Shadow Dancer, even the Master System port of Ghouls 'n Ghosts changed things such as the shop).

I've long believed the map was originally planned to be in the 16-bit version. It let's the player know the story is even taking place on an island and that the "Zones" are actually zones of the island.

It was more than likely removed to avoid any Mario similarities. But removing it only added to the misunderstanding of the story and Sonic's world.