If the earth's landscape was flat how far could someone see?

Question

How far can someone see until they cannot see around the curve of the earth? I know it may depend on were your are on the earth since the earth is not completely circular so give me a few examples of different places if you can.

Answer 1

You can ignore the earth's departure from a circle for this purpose. Distance to the horizon varies a lot with the elevation of your eye from the ground, so you get varying numbers.

Answer 2

If you simply looked it up, you'd know that at sea level one can see 13 miles.