Ascension... let's get started

[dr Jack]

The roads are big because I wasn't good to draw them :p.
They're the biggest road in the city, and maybe a little bigger than normal. But not so big like in this sketch.

The ancient civilization created them to help the troops to go in the middle, but now it's a normal city e no more a siege engine city, so someone have build on it.

The market of the city is the one in the center, the blue thing is a huge portal where they took in food and other goods. They come from everywhere.

The edge is used less. The traffic is more in the center.

The city can move, but the lake is not an ocean. They use it as a good defence.

Well, the city economic is based on tertiary sector.
Scientist, lawyers, magician, medics, archivist... ecc.

I think the city idea is really more complex than his map :p.

For now I read this tutorial.
Within some hours I plan to read and applicate this or this.
But they're both for photoshop, if you know something better for Gimp / Inkscape, or you think there's a better tutorial for my idea, I'll be delighted to use it.