In North Ontario, Canada, and in some parts of the East coast, many speakers use the words "up" and "down" to refer to elevation rather than direction. So you would say "I'm going up to the store" only if the store was higher in elevation than where you were currently standing, even slightly.

I grew up in North Ontario, but my parents were not native English speakers, and it was only in my late teens that most of my friends (who had native English speaker parents) were using the terms this way. I used "up" and "down" interchangeably.

What amazed me is that this implied an intrinsic awareness of elevation, which I didn't have; everybody else always knew if your house was higher than their house.

In some cases, the up/down distinction was used in place of left and right. In fact, I learned about this distinction sitting in a car at an intersection and getting the directions "just go up the road", as if that was totally unambiguous.