This is a continuing series of worldbuilding and fantasy cartography projects. They are entirely fictional places but have enough realistic geography, environments, and history to create many types of maps and maybe parts of an atlas.
Praemaria is a replacement for North America. I got as far as a National Geographic style map before realizing it was way too big. It would take forever to fill it in with the all of the maps I wanted to make.
Instead, I decided to imagine a smaller land in the South Pacific that was far away from other places and that had its own unique history, culture, languages, religion, and governance with Polynesian and European influences. Location and terrain would determine realistic weather, agriculture, transportation, etc. All of these would be mapped.
Matatuaroi, about 1/3 larger than New Guinea, has real terrain from USGS heightmaps that I chopped up and blended into a single island image using a photo editor. I located the image in the real world with a geographic information system and then exported it to a vector graphics program. This project resulted in a political map, a set of thematic (temperature, rain, etc) maps, and two history maps. But, it was still too large.
Hotūpo is in the same location, but smaller still. With Hotūpo I imagined that Captain Cook charted it on his second voyage in 1773.
The Opōno Islands, comparable in size to the Hawaiian Islands, are the most recent. I used a terrain simulator which allowed me to create realistic 10 meter topographic maps in the GIS.