Every season, Nerva City reenacted the Olympic ceremony, although a lack of information in the archives meant it happened "every fourth of a year", rather than every four years. Furthermore, much to Flip's surprise, it did not involve any sport. (AUDIO: Wirrn Isle)
Built in 16087 on the former site of New York City to afford the protection of its natural harbour, Nerva city was the the first major colony founded by the people who had been cryogenically frozen on the Nerva Beacon.
The Sixth Doctor and Flip visited the city in 16127, before accidentally transmatting to the a colony on Inchfad Isle. Soon after, Paul Dessay announced that all transmats would become one-way only, in order to encourage the growth of the new colonies around the world.
That day, Wirrn, which had been frozen under Loch Lomond for over a decade, invaded Nerva City. The Doctor stopped them by transmatting them back to the loch before freezing it over once more. (AUDIO: Wirrn Isle)