Doctor Who: 10 Places The Doctor Has Never Visited On-Screen

10. The Zygon Homeworld

Referred to as 'Zygor' in extended media, the home planet of the Zygons has never actually appeared on TV.

Said to have been destroyed in the Time War in 2013's The Day of the Doctor, the shapechanging Zygons have never been depicted occupying their own planet in the show.

In 1975's Terror of the Zygons, the Zygons had fled to Earth in the 12th Century when their planet had been destroyed 'in a recent catastrophe.' In this adventure, they had tried to overpower and occupy the Earth, despite being few in number.

To assist in their conquest, they deployed a Skarasen - a cyborg creature native to their world. The Skarasen, residing in Loch Ness in Scotland, became known as the Loch Ness Monster and had held a legendary, mythical status for centuries.

Defeated by the Fourth Doctor, Sarah Jane Smith and UNIT, the next appearance of the Zygons was The Day of the Doctor where they again, were trying to colonise Earth.

Realising that the 16th Century Earth they had crashed in wasn't technologically advanced for them to dominate, they froze themselves in stasis cubes to be woken in the 21st Century. During this adventure, and 2015's The Zygon Invasion/The Zygon Inversion, the Zygons continued their bid to conquer the Earth - with many displaced Zygons even being allowed to seek refuge across the planet.

We're yet to see the Zygons in their natural habitat, but with 2017's Empress of Mars finally depicting the Ice Warriors on Mars, the Zygons might have a home sooner or later.