Titan (moon)

Titan was a moon in the Sol system, orbiting the planet Saturn. Titan is the largest moon of Saturn, and the second largest moon in the solar system. It's the only moon to have a dense atmosphere, and is larger than some planetary bodies in the solar system.

Humans had established a colony on the surface of Titan by the mid 21st century - which was covered by a series of domes. The colony became a safe haven as Earth was ravaged by World War III. Zefram Cochrane spent time at the Titan colony. The colony still existed 200 years later, and Zefram Cochrane was laid to rest at the colony. (Star Trek: Federation).