Whomever gave the locations above were completely wrong, the correct locations are:
Amon Varadh 27.9s, 14.9w
Barad Glamgil 28.8s, 14.1w
Minas Ciliant 26.8s, 15.1w
Ost Brandras 27.9s, 13.5w
Ost Chall 27.1s, 13.8w
Ost Durgonn 31.8s, 20.7w
Ost Thondol 31.1s, 13.2w
Trapdoor Lair 26.1s, 18.5w