Juneau is a city in Alaska, one of the most northern most cities on North America (but not the most!) because it is a port city, it is generally well know.

Tierra del Fuego is an area (not sure if it is a state, county, island, (group of islands?) at the southern most tip of south America, close to the the straights of Magellin.(part of Chile, i think)

smj could have said "St John's" which is a town in Newfoundland on the East coast of North America--and spanned the continents from east to west as well as north to south!

we have a canadian friend from there, (Hi Bean!)but to my mind, Newfoundland is not nearly as cold -and so i don't think of it as being as northern as any place in alaska-- as for actual latitude, i don't know!