As an urban planner, I love maps. And, as someone casually fascinated by language/linguistic geography and sociolinguistics this is so interesting to me! I come back all the time as I’m exploring new neighborhoods. Done by the good people at the Endangered Language Alliance.
Another fascinating project (and mapped in, like, HTML) is this interactive map done by an amateur linguistic geographer, North American English Dialects, Based on Pronunciation Patterns.