While other posters mention the use of keys, I just want to point out that if all you're interested in is the values, you can use the values function to just pull those out:

foreach my $value (values %coords) {
   printf("%d-%d\n", $value->[0], $value->[1]);
}
[download]

Also, be sure to remember that hash order is not guaranteed. If you need these things to be ordered based on the hash key, you'll need to use sort in conjunction with keys as in others' examples to accomplish this.