# declare $grid to hold ref to anon hashes (thanks tye)
my $grid; 
for my $x(-5..5) {
    for my $y(-5..5) {
        $grid->{$x}{$y} = "co-ords x:$x, y:$y";
    }
}

print "Here is -2,3 : ", $grid->{-2}{3};
print "\nHere is 0,0 : ", $grid->{0}{0};