(CNN)-- Tokyo was known as Edo until 1868, but it's hard to imagine that this high-rise, high-tech metropolis could possibly have existed in a time before electricity and concrete. Tokyo isn't just a ...

(CNN)-- Tokyo was known as Edo until 1868, but it's hard to imagine that this high-rise, high-tech metropolis could possibly have existed in a time before electricity and concrete. Tokyo isn't just a ...