Kaernor's Smile was a large chasm on Tilnes. Minerals within the walls of the chasm drained power from ships attempting to fly through it, sending them plunging to the bottom. The crevasse was nearly 40 kilometers long, almost 2 kilometers wide at the middle, and over a kilometer deep.

The Smile was considered tainted and unclean, with nothing seemingly growing there. Anybody who slept near Kaernor's Smile would have the same dream of battles and violence, led by two mysterious dark figures who suddenly identify the watching dreamer and redirect their armies against him. The dreamer then had a traumatic awakening. However, as the dreams had been documented for generations as of 32 BBY, some believed that they were caused by a cultural effect of the tale.

The Smile was perhaps strong in the dark side. However, nearby Jedi found no dark side taint in it, and they were familiar with a dark side site because of the nearby Almas Sith fortress.

It was named for Kaernor Belasstie, one of the miners who disappeared inside it.