Thanks for the ask anon!!!
I did have a map for WCTD, but it was so old and outdated that Aetier was still a kingdom that bordered fantasy fake Germany. So to answer this ask, I went ahead and made a new map! (Shout out to Pris @serpentarii for sending the map tutorial they use, I owe you my life). It's not super duper accurate, just because there are details I forgot to add, and I'm still squinting at the general shape of the borders, but its mostly correct.
When Comes the Dawn takes place on the continent of Raia, primarily in the Aetierian Empire. Below is a map showing Aetier and its two plot-significant neighbors, the kingdoms of Hesperia and Leohthal
The empire owes much of its prosperity to their control over the Iphegenian Sea, considering as its a gateway of trade between the continents of Raia, Ior (to the east), and Ostri (to the south). The Empire's capital, Kaelstanopoli (not marked), was at the center of this trade route.
Important geopolitical developments for WCTD though is Hesperia coming under Aetier's rule during the Hes-Aei war (though most people in Aetier just call it Dantalion's Hesperian campaign).
Below are pre-war (before the book) and post-war (when the book starts) maps of Aetierian territory.
Fun fact! Hesperia and Aetier used to be one country, with Hesperia being the empire's "birthplace" and eastern/south-eastern Aetier being the financial capital. Hesperia's secession from the Empire occurred during the Era of Three Crowns, a period of civil war where 3 vi Aetier heirs (Anastasia, Theophanes, and Karas) waged war against one another for the throne.
Long story short: Anastasia defeated Theophanes and declared herself Vasilier. Karas seceded his territory from Aetier and became king of Hesperia. Both groups were too exhausted with fighting to continue on (though the rivalry between both countries persisted through the centuries).
Not exactly sure what to cover with geography, so if you have any more questions, feel free to send an ask!