General Question: Map Size/Scale

I have a landscape that 2000x2000x2000 and I’m having difficulty understanding what that translates to. My character was on one end and literally ran for 43 minutes to reach the opposite side and fall off the world. Its certainly not centimeters(.012x.012x.012 miles) or meters (1.2x1.2x1.2 miles) but it seems to quick a sprint for kilometers (1243x1243x1243 miles).What does 2000x2000x2000 represent?