This weekend I was at a conference where a large number of the speakers happened to be Canadian. It struck me that a large number of Canadian toponyms have different pronunciations in Canadian English and American. Some examples:
Canadian M/ʌ/ntreal vs. U.S. M/ɑ/ntreal
Canadian Newfoundland vs. U.S. Newfoundland
Canadian Tronto [or even "Chronno" - thanks, mzn!] vs. U.S. T/ɚ/onto
I think that the pseudo-French pronunciation of Quebec as /kebek/ in Canada is a different, and later phenomenon, a sort of particularly Canadian political correctness. But the others are simply place names for which separate American and Canadian pronunciations exist, each of which are the only legitmate option for Anglophones of the respective countries. For instance, though I'm American, I've started saying M/ʌ/ntreal, which is an affectation, and I'm annoyed with myself for it. Perhaps my excuse is that I'm a quarter Canadian (my Grandmother was Canadian). No, that's no excuse.
I tried to think of other examples of this phenomenon of different pronunciations of toponyms within a language (aside from ones you can explain with reference to dialect differences), but I could only think of a few. For instance, Oregonians get huffy any time they hear "Oregon" with secondary stress on the last syllable and no vowel reduction. Little do they know that the only people who say Oreg̚n are from there (or those like me who have lived there and had the mainstream pronunciation beaten out of them.