Theta VIII, the location of the recreation of the Royale Hotel
Theta 116 system was a star system that had remained unmapped by the United Federation of Planets until 2365, containing eight planets.
In 2365, the scattered remains of the
21st century Earth spaceship were discovered in orbit of the farthest planet Charybdis Theta VIII in this system by a Klingon cruiser. Subsequently the USS entered orbit to investigate. ( Enterprise-D : " TNG ")
Before "The Royale", two other Theta planets have been mentioned in Star Trek. Theta III seen on a star chart and Theta VII, a colony planet, where USS delivered vaccines after the events in Enterprise : " TOS " set in Obsession 2265. According to Star Trek Maps (page 30), the Theta VII colony was located around the star Theta. According to the FASA source book The Federation it was in the Theta Gamma system.
The Theta 116 system was presumably at least 315
away from Earth, since Picard noted in "The Royale", that a mid-21st century Earth ship (before
was invented) could not have traveled that far out.