wind breaks
once humans start staying on Mars for extended periods of time, we'll probably need "wind breaks" around bases to cut back on unrestricted wind flow. In short, a long row of 2 story buildings just might do it. If these contain hydroponics or regular greenhouses, that's even better. To combat the Dust Bowl of the 1930's, trees were planted for the same reason. And to sustain extended stays, we'll need to grow food. SOooo, greenhouses of some kind, built in a single long row, with other structures near the center.