I remember over 15 years ago my wife and I were honeymooning in Europe (rom the US). While we had iOS devices that could use maps, the data services then were terrible, and GPS was effectively useless
We ended up taking screen shots of Google Maps where we zoomed in on local streets, on an ad hoc type atlas. I wish we had this app back then
At that time I think I was using CityMaps2Go. Not sure if it still exists though.
I believe MapsWithMe (now Maps.me) was released about that time, but I personally didn't get an iOS device until 2013.