Aridius

Aridius was a planet originally covered by oceans. Due to a stellar incident, its orbit around its suns turned the planet into a desert over a thousand years.

Astronomical data
Aridius had high levels of oxygen and its gravity was a little greater than Earth's. (TV: The Chase)

History
After the ocean planet had become a vast desert, the only remaining species were the amphibious Aridians and the octopus-like Mire Beasts. To control the Mire Beasts the Aridians blew up sections of the city that had been overrun.

The First Doctor, with companions Ian Chesterton, Barbara Wright, and Vicki Pallister, visited Aridius, but were tracked by the Daleks, who pursued them in a time machine. The Daleks tried to force the Aridians to hand the Doctor and his companions over, but they escaped before the Aridians could do so. One of the Daleks guarding the TARDIS was tricked into falling into the tunnels, enabling the TARDIS crew to escape. (TV: The Chase)

The Daleks later returned to Aridius, still remembering their encounter with the Doctor there. They wanted revenge on the Aridians and wiped them all out along with the Mire Beasts. (PROSE: The Sagarro Desert Storm) During the Last Great Time War, Romana II acknowledged Aridius as a planet which had been invaded by the Daleks. (AUDIO: Beyond)

When the Eleventh Doctor visited the Dalek Asylum, he learned that some of the Daleks in the intensive care section were said to have survived an encounter with the Doctor on Aridius. (TV: Asylum of the Daleks)

Behind the scenes
Romana's mention of the Daleks invading Aridius in Beyond, in addition to planets exclusive to Dalek Wars is evidently a reference to this event rather than the smaller-scale incursion seen in The Chase.