The surface of Srangor had many mounds, which the Doctor claimed were factories being used to build Dalek weapons. Large cities were present on the planet before the Daleks invaded. The Daleks had also burrowed to the core of the planet. (AUDIO: X and the Daleks) There was also a mountain on Srangor. (AUDIO: Fugitives) Due to the effect of Time Lord weapons being used on the planet, regeneration was impossible there. (AUDIO: X and the Daleks)
By 1893, the Daleks, with the help of Kotris, began to construct a Temporal Chamber inside the planet, and the Dalek time controller used the planet as his base of operations. The Eighth Doctor and Molly O'Sullivan arrived in 1983 and met the locals of the planet, who lived in fear of the Daleks.
The influence of the Daleks on Srangor was erased after the timelines were re-written when Straxus was killed on the planet by the Daleks. Because of this, the Daleks never invaded Srangor. (AUDIO: X and the Daleks)