Ophidian

Ophidian was a Silurian city that developed in an alternate timeline created by the Monk in which the Third Doctor was killed in Wenley Moor during the awakening of the Earth Reptiles.

With the Doctor's death, the Silurians and the Sea Devils rose from hibernation to become the dominant species on the planet. Over the next twenty years, they began the slow process of terraforming the world back to its original condition during the Earth Reptiles' original rule. This saw the reintroduction of dinosaurs into the ecosystem and the planet's cities overrun by jungle as well as humankind being driven to the brink of extinction. Once they had completed this work, the Silurians created the new capital city of Earth, which was called Ophidian and was located in Africa.

The Seventh Doctor, Ace and Bernice Summerfield fell into this version of Earth through a hole in the Time Vortex. Over the course of events, the Doctor travelled to Ophidian where he met with Morka, who had come to regret his actions and attempted to form a lasting peace with humanity. However, the vengeful Brigadier Lethbridge-Stewart, wanting to destroy the Silurian race, unleashed a dinosaur stampede in Ophidian which killed many Silurians. Afterwards, he launched a nuclear missile at Ophidian. The Doctor was able to prevent the detonation of the warhead through the use of the TARDIS and saw to it that Earth Reptile and humans made a new peace. (NA: Blood Heat)