Local pronunciations of place names are often different from what's expected, and whether intended to be such or not, are often used as shibboleths to distinguish locals from outsiders. The examples of Couch Street (/ˈkutʃ/) in Portland, Oregon and Tchoupitoulas Street (/ˌtʃɑp.ə.ˈtuː.ləs/) in New Orleans, Louisiana come to mind in American place names.
Tchoup is just unpronounceable to most outsiders; the shibboleths are the streets that are pronounced very differently from what it would be anywhere else. Like Calliope (rhymes with TALLY-hope) or Burgundy (emphasis on second syllable).
Or Chartres ("Charters") or Melpomene (/ˈmɛl.pə.ˌmiːn/), I get it. My wife has corrected me on quite possibly each and every one of the streets with a locally specific pronunciation.
Ooh, thought of another good place name like that: Quincy (/ˈkwɪn.zi/), Massachusetts! Massachusetts has a fair number of those, owing to its English settlement heritage.
I wasn't referring to place names that sound like dirty words (as Couch St. sounds like "Cooch"); an uncountable number of Gropecunt Lanes in England would certainly qualify. I was rather referring to place names with counterintuitive pronunciations locals are expected to know, so that outsiders are immediately clocked by pronouncing it wrong. Couch St. definitely qualifies in both categories though.
