Designing a city map from scratch is considerably easier than mapping an existing fantasy town, many of which do not make sense in practical ways. Cities grow from successful settlements and change over the centuries in ways which are fairly predictable, as common requirements dictate. The reasons for a settlement being where it is, and the landscape itself shapes the way a city changes. These sketches are based on real town maps of the 15th and 16th centuries.
Because the size of Titan has yet to be decided, the map area above is not to scale but still gives an impression of the landscape. The type of bedrock, water aquifers and shape of the hills all have implications which help narrow down the options for development later on.
First draft for the 3D map area.
A more detailed map showing possible land use and the different trade quarters one might expect in a growing town. One of the principle aspects of town layout is the fresh water supply, irrigation and, of course, plenty of underground (or covered) rivers and sewers to dispose of the enormous amount of refuse generated in a town of this size. "Wooden hills" should read wooded hills.
Based on a 14th century town plan, the 3D sketch above shows a citadel and defensive structures, viewed from the northwest. The four islands are artificial. The moats have been cut into the landscape and bridged strategically. Once these are in place, the rest of the city and the faubourgs (literally "out of town") can be planned around it.
These initial sketches are speculative but seem to work quite well, despite the fact that the landscape doesn't quite match the 3D map of the area around Salamonis. Feel free to use this as a base for designing your own towns and cities.
