Did the Romans have maps or knowledge of Southern Africa/Northern Europe or what lay beyond Hadrian's wall? Edit - Around 100-300 AD at the height of the Empire.
Did you know that the Romans and Chinese actually had direct relations?
The History of Later Han (後漢書) states that the first official contact between the two empires occurred in 166 AD, near the end of Pax Romana and the first Pax Sinica of the Han Dynasty
大秦國王遣使奉獻
The King of Great Qin sent ambassadors to pay tribute.
Qin (秦) originally referred to the predecessor of the Qin Dynasty. It was slightly less modern than many other dukedoms during the Spring and Autumn Period and the Warring States Period (春秋戰國時期), so it was considered to be outside of the world of the Huaxia (華夏 later known as the Han Chinese) people. Since it lay west of the Huaxia world, this term was later used to describe the Romans, who were west of the Huaxia world, as a powerful counterpart to the Han Empire
We know that an Antoninus (安敦) sent the Roman ambassadors to meet Han Huandi (漢桓帝) in the imperial capital of Luoyang (洛陽), but it is unclear whether it was Antoninus Pius (who died only 5 years earlier in 161 AD) or his adoptive son Marcus Aurelius Antoninus Augustus. Although the Romans brought many gifts, their treatises on astronomy were the most significant to the Chinese
The two empires knew that the other was on the opposite end of Eurasia. Ptolemy's Geography shows Serica (Land of Silk) and Sinae (Qin Empire, the first Chinese dynasty) on the far eastern end, but we can see that the Romans seemed to have a murky idea of China despite the distances involved. Of course, this went both ways
In 97 AD, a Chinese official named Gan Ying (甘英) reached Mesopotamia and gathered lots of information about Rome, but never actually set foot on Roman soil. Some of his information was inaccurate as well, such as placing Rome west of the sea, meaning in the then-province of Egypt. But it seems that he largely gathered great information on Rome for the Chinese
There were other Roman-Chinese contacts, but the Antoninus mission and Gan Ying stand out the most in my mind
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