I am totally new to all this so please be gentle if my question is stupid or has been asked before somewhere.
I have just been playing around with the Virtual moon atlas and noticed something that has me very puzzled.

Overall, the moon has craters spread fairly evenly across its surface EXCEPT for the two poles where they seem to be concentrated into a very small area.
It seems strange that nowhere else has such a large amount of impacts in TWO relatively small areas
So my question is . . . Why have these two areas had such a concentration of meteor strikes ?
Please and thank you