didn't make this before, but if it's not isometric view, I would use for e.g. arrays
https://www.scirra.com/tutorials/307/ar ... ers/page-4
1.) set size of array
2.) fill array with random numbers
3.) read arrays and transform it (e.g. 1-> water, 2-> land, 3-> mountain, 4-> city)
you can also make some fine adjustment:
e.g. when more 25% of array is water, then run again random filling