A city on the Moon, named after the crater Tycho, that Riker lists among the lunar settlements visible from Earth in Star Trek: First Contact.
Tycho City is one of the major settlements on Luna, Earth's Moon, taking its name from the prominent crater Tycho in the southern highlands.
It is mentioned in Star Trek: First Contact. In Montana in 2063, Zefram Cochrane shows Riker the Moon through his telescope, and Riker remarks on how different it looks. In his own time, he explains, some fifty million people live there, and on a clear day Tycho City, New Berlin and even Lake Armstrong can be made out from Earth.
The exchange is one of the few glimpses the films give of everyday civilian life in the 24th-century Sol system. The city is never shown, and it stands mainly as a measure of how far humanity is to travel in the three centuries after Cochrane's first warp flight.