If it helps, the London metro is ~3200 square miles, and has more than twice the population of Atlanta (14 million vs 6 million). Paris is ~4600 square miles w

If it helps, the London metro is ~3200 square miles, and has more than twice the population of Atlanta (14 million vs 6 million). Paris is ~4600 square miles with 13 million pop. Berlin's full metro is actually comparable. It's about 11,000 square miles, but it's also nearly 1/10th of ALL of Germany.