My city is grid based, but downtown is rotated 45 degrees from the cardinal directions. This leaves me constantly confused and confounded while downtown, not least because the transition streets from downtown to the rest of the city are all at crazy angles (that is, unlike anything where I grew up).

As you say, this isn't a language feature. For me the concepts of N,E,W,S and the easy visualization matters more than my language. I picture a map, but not the words on the map.

fascinating. what city?

It sounds like you're not a native -- in your observation, is the ability to navigate easily in the 'rotated downtown' area correlated with having grown up nearby?

That would make a cool study.

Denver does this; not sure if that's the OP's city, but you can see the relevant bit here: https://www.google.com/maps/@39.7565211,-104.99244,14z

I'm in the Central Valley (CA), and I notice that this is a pattern that seems to be repeated up and down the 99 (Downtown parallels the freeway while the rest of the city exists on a normal grid).

Montreal works this way -- the street grid is aligned to the St. Lawrence rather than to compass directions

> natives of grid-based cities can always find north as well

I live in a grid-based city and I would dispute that. I'm pretty comfortable with cardinal directions but that hasn't been true of nearly anyone I've tried to provide directions to.