Exxilon

Exxilon was the home planet of the Exxilons.

Astronomical Data
Exxilon was an ancient planet, significantly older than Earth. It orbited a sun which was both larger and closer than the sun of Earth. Its sky was copper in colour. Due to the influence of the Great City of the Exxilons, it was a barren planet, covered in deserts, sand dunes and rocks. The seas had dried up, leaving behind few lakes. It was bitterly cold during the night and unbearably hot during the day. There was little in the way of life on the planet. Exxilon was rich in Parrinium. (DWN: Death to the Daleks)

History
At some point of their history, the Exxilons decided develop something that would outlast time itself, creating the Great City of the Exxilons. The City was intelligent and capable of repairing itself allowing it to survive for thousands of years. The City turned against the Exxilons, though, and drove them from the City. It also drained all the energy from the planet, leaving it barren and desolate.

During the space plague, Human and Dalek forces came to planet in search of Parrinium, but were trapped when their ships ran out of power due to the Great City. The Doctor and Sarah Jane Smith also came to the planet by accident, and were likewise trapped. The Daleks modified their weapons and enslaved the Exxilons and Humans to collect the Parrinium, as well as sending Daleks to investigate the Great City. The Doctor also investigated the city and was able to stop it from draining energy. (DWN: Death to the Daleks)