It's very nice, I love all the details. A nice combination of what looks like quite distinctly different districts. There seems to me to be an aura of viligance against attacks, considering the wall placements and the gate.

But it seems odd to only have the one gate. It would SEVERELY hamper any trading if all traffic needs to go though that one gate. Are all the other areas where the city has spread islands? If someone in the top Eastern district wants to just leave the town it would take an hour to just leave the city.

If there's a great reason for the singular gate, consider making those streets into very wide avenues, including the main bridges. Perhaps some smaller bridge of wood to the North East (I guess that's an important district) as well that can easily be burned if there should be an attack on the main gate. Regardless, you'll need very well oiled transports in the city as everything from food to building materials and trade will have to pass these streets.

To be fair though, it doesn't look overly hard to simply land boats and invade from the shores inside the city. Medieval naval warfare was mostly just about dropping off men somewhere.

On the whole, though you've done a great job!