The City of Gold (The Tripods)

The City of Gold is the name given to the dwelling places of the Masters in the novel The City of Gold and Lead (1967), the second book of John Christopher's trilogy, The Tripods.

There are three such cities from which the Earth is ruled and from which humanity is kept docile and obedient. There is a European city near the ruins of Berlin (hinted, in the book as being on the eastern side of the Iron Curtain), an Asian city in China and an American city that straddles the Panama Canal.

Conditions within the city are oppressive and harsh. The gravity is over two times that of Earth's and the temperature is extremely high. (This high gravity explains the book's title, The City of Gold and Lead.) As well as this, the Masters breathe a different atmosphere to humans, so within the city all human slaves must wear masks with filters.

Each city seems to follow the same basic design. There is a circular golden wall bounding the city that is approximately 150 to 300 feet high (only estimates are given throughout the book). Above this wall is an emerald-green dome of crystal that separates the atmosphere of the Earth and that of the city. The golden wall is described as being smooth, seamless and featureless.

Although most artwork shows the contents of the city reasonably clearly the books imply that the structures inside are quite invisible, at least from the viewpoint of the ground. When flying over the American city in a balloon in The Pool of Fire the narrator describes being able to see the tops of the structures, albeit very dimly.

The main opening into the city is through a triangular door, slightly higher than a Tripod. This leads to a vast garage (described by the narrator as a stable) where the Tripods are stored and the slaves unloaded. In the book The Pool of Fire it is described that the Tripods have airlocks allowing them to dock with chutes in the walls of this garage, allowing the Masters to leave them and enter the City proper without having to venture into the oxygen atmosphere of the garage.

From the garage is a small changing area where new slaves are given clothing and equipment suitable for life in the city. This leads on to an airlock-lift that takes the new slaves to the city's "Choosing Place" and into the poisonous green atmosphere of the city interior.

...
Wikipedia