Yet again the DW production crew descend on a snowy Caerphilly Castle. Back in January they were there for The Vampires of Venice and now the current block again makes use of one of the largest castles in the UK.

After hearing about the base in the car park the kids and I headed down for a gander, just like we had before. We parked in town, walked through the precinct and headed up to the castle. Sitrep - cold and icy underfoot. On the way up we could see a panalux van or two by the main gate and plenty of activity too. Lots of people on site, so this looked like it was going to be a big shoot.

As we got closer, a silver car pulled past us and out got Karen Gillan. She was well wrapped up but it was easy to spot her flame red hair in the bright sun. She rushed up into the castle and we followed slowly behind, paying our £10 entry fee on the way.

Walking up the hill we could see metal girder-like props on the the floor by the side of the buildings, some were getting a last minute spray to finish them off. By then I realised it was very early in the shoot. Walking through the east inner gatehouse it was obvious that this was where all the action was going to take place. Kit and wires galore in the buildings on both sides of entry.

Carrying on we looked around the rest of the location. Nothing was happening in the Great Hall at the time we were there (10am) but as time went on it looked like some kit was being placed in there. Towards the back of the castle a number of plastic container drums were being stacked, they seemed out of place for a castle setting but then again so did the girders.

Every now and then people would come out to the concession table for a cup of something warm. At one point we saw a trio of male cast members in orange trousers. At first I thought they were boiler suits but then noticed they all had what looked like white tunics poking out from under their winter coats.

We wandered round the castle a bit more and found our way into the upper corridor which runs along the back of the great hall. This was used for part of the chase in VOV but today didn't seem to be dressed or lit for filming. It does however lead to the side entrance to the upper levels of the east inner gatehouse but that doorway seemed to be locked. So no luck there then.

Venturing back into the inner keep we saw a couple of strapping lads carrying kit up into the north west (lady's) tower. As there seemed to be no one up there, we had a wander up there too. This leads up to a balcony area that looks out onto the keep and further up to a circular room. This is where the kit ended up. There also seemed to be a large round wooden stucture in that room too which may be part of the episode.

While we were in the shop, a quad bike which they were using to get a round on the icy ground drove past. On the back was a silver cylinder, approx 1.5m high and 0.5m across with two clock/dial/gauges on it. It looked like it would be part of some larger machine and certainly fit with the other set props we'd seen earlier.

So thats my report for today, I doubt filming will be visible when it starts and its quite possible they'll be there after the castle closes at 4pm today and maybe into tomorrow too. One final thing. Its bloody cold at the moment, spare a thought for the crew who work hard in all weathers to bring us our favourite TV show. It was -4°c when we arrived; it will warm up slightly but it'll be much colder later.