[History] ORBIS: The Stanford Geospatial Network Model of the Roman World
orbis.stanford.edu
Stanford has a tool to calculate travel times in the Roman Empire. A great resource to get a better perspective of the world they lived in. I like to use it for writing stories in settings with similar technology levels, to get an idea of how quickly people should be able to travel.
I read about this in Mary Beard's SPQR. Highly recommend that book if you're just starting out learning about Roman history, particularly Cicero.
Awesome, I hadn't heard of it but thanks for calling it out! A link with more info for anybody else that's interested.