Some old maps from ancient Rome are only showing parts of Europe and northern Africa but as far as I know there was some trade going on between Rome and the Han Empire.
So,... What did the Romans really knew about eastern civilizations (or even american civilizations) and how did it affect their view on the world?
Regarding Roman contact with China, check out the related FAQ section, as well as this previous thread:
I've read somewhere that ancient China and Rome were each aware of the other's existence. Is that true? by /u/threechance