A ravine was a geographical formation similar to a canyon, but narrower; and was similar to a valley, but with steeper slopes.
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")
In 2373, Zahir was found unconscious at the bottom of a ravine near a Mikhal Traveler outpost. (VOY: "Darkling")
In 2375, a Starfleet force, led by Benjamin Sisko, placed subspace mines in a ravine on AR-558 to detonate them when attacking Jem'Hadar passed through it. (DS9: "The Siege of AR-558")