Kulma Narrows used to be a populated region located on the planet of Naboo.
The author of The Essential Guide to Warfare, Jason Fry, ultimately decided to remove all references to Kulma Narrows from the finished version. Sometime later, the locale became canonical via the StarWars.com blog post titled Star Wars: The Essential Guide to Warfare: Author's Cut, Part 6 — Showdown at Naboo.