A ravine was a geographical formation similar to a canyon, but narrower. In 2153, Phlox and T'Pol got infected with a microbe on a planet they explored. Phlox speculated they were infected in the second ravine the two had entered. (ENT: "Bounty") In 2269, a group, including James T. Kirk and Spock, blocked a ravine on the mad planet to block the flow of lava. (TAS: "The Jihad") In 2371, when Kira Nerys and Shakaar Edon hid in the Dahkur Hills, Kira projected false lifesigns about 700 meters past a ravine to confuse the pursuing Bajoran Militia. (DS9: "Shakaar")