Is the original map still existent? I can only find copies of the map and most of them are showing a place in the region of Mauretania called Atlantis(means Island of Atlas). Interestingly enough the first king of Mauretania was called Atlas and the desert there is filled with seashells.
The map is neither real nor a hoax. Herodotos did not make any maps; there is no "original map". The maps you've seen were made thousands of years later, based on his work, to help modern readers keep track of all the peoples and geographical features Herodotos mentions. One of these features is Mount Atlas, and one of these peoples is the tribe of the Atlantes (= the people of Mount Atlas). Herodotos never mentions any place called Atlantis.
I wrote a little more about the map here and also more about how to read the map here.