[PTTG]

Since we're on the topic of timelost cities, how about we take a big circular section from modern Africa and send it back to the Scramble (or earlier), abruptly reversing the technological gradient?

My first thought was something including Nairobi and Mombasa, presumably taking a big bite out of northern Tanzania too.

Alternatively, we could take a similar-sized area from the west coast and move all of Liberia, which would immediately have an interesting and complicated connection to the United States.