I'm trying to come up with ways to find one's bearings on a flat world. Here's a mock-up map I have used on the two previous discussions on the topic.
So, we have a flat plane with a sun relatively low above the center and a bunch of sky-island type shades providing the day-night cycle. If you let go of an object you're holding, it accelerates downward at 10 meters per second squared because Things Fall Down, and there's definitely magic involved somewhere, but I'd like to keep the mundane physics as close to the real world as possible. However, there isn't a magnetic field because there is no giant ball of hot iron spinning to create it.
During the day, the sun is of course a landmark you can orient yourself by, and you can find your latitude by the angle of the sun.
But, how would you go about finding your bearings during the night, or with an overcast sky, and how to determine one's longitude? Are there some weird tricks for navigation on a flat world that don't work on a spherical one?