Zanor is one of the few countries on Sasoom that has remained unconquered by the Morgors. Zan Dar describes it to Carter as a land of tremendous mountains, thickly forested with trees of great size and height. The tallest mountain rises twenty miles above sea level. The mountains and thick forests make it an easy place to hide from, and defend against, an airborne enemy like the Morgors, although Zan Dar believes the Morgors could eventually conquer it if they really wanted to. The reason they don't is because it's not worth the effort since it would require lots of men and ships. The island is now mostly used by the Morgors to give new recruits some practice at warfare by sending them on small scale invasions against the Savators.
After escaping imprisonment, Zan Dar, Dejah Thoris, Vorion, Vaja and U-Dan flee to Zanor in a stolen ship. At the end of the book John Carter also makes it to the island and hopes to be reunited with Dejah Thoris there.