The official website reveals: “The exterior of the time machine will remain the reassuring blue box but once inside we’ll see a whole new magical world that will be home to the Doctor and Clara…”

Steven Moffat explained the changes at a screening last night in London: “I thought we’d been getting progressively whimsical with the interior of the TARDIS. And I started to think, ‘Well, why is that? It’s not a magical place. It’s actually a machine.’ And actually potentially, as you’ll see more spectacularly later, quite a scary place sometimes. We make a lot of use of that.”

The new set was designed by Michael Pickwoad, the show’s production designer since 2010.

‘The Snowmen’ airs on Tuesday 25 December at 5.15pm on BBC One.

Are you looking forward to the new TARDIS set? Let us know below…

> Buy Series 7 Part 1 on DVD on Amazon.

Watch the Christmas special trailer…