There was some filming that sneakily happened yesterday, but which was luckily caught by emmag892

So here's a brilliant set report and photos courtesy of her:

Whilst out and about with friends yesterday i got a call from a relative who informed me that a load of vans were parked up in WOOKEY HOLE CAVES car park...

DT turned up about half six and went straight into his trailer... We then walked back to behind the base and stayed there for a bit but everybody seemed a bit edgy, DT was running everywhere so nobody could get a good picture, and there was a few extras dressed it what i could only describe as tunics kinda monk like.

I overheard them saying they were filming in the "witches parlour cave" bit which from visting before is quite deep in the caves. At about 7.40 pm DT then got into a car and drove away to the caves which is when we left.

You can see a 360 degree tour around the Witches Parlour here and it seems very other-worldly indeed!

And monk-like people makes me think (or maybe just hope) that its Time Lords. Then again, I'm sure it could be anyone.