Fake places that existed to catch copycat cartographers
This is pretty cool: some mapmakers would put fake towns on their maps in order to catch copycats.
The General Drafting Company created the town of Agloe, New York in 1937:
Google created the fictional town of Argleton, UK. (More from Huff Post.)
Nomad List created the fictional Japanese city of Dorobō, which means "thief" in Japanese.
Do you know any other examples?