A film crew was working on the Doctor Who centenary special at Hodge House in Cardiff on September 15, 16, and 17. The Hodge House, constructed in 1915, is a landmark listed, eight-story building on St. Mary Street in Cardiff’s City Centre. The interior of the building had recently been renovated into modern office space. Filming occurred inside the building, where someone snapped a photo of the UNIT logo on the floor. While there are rumors that extras were hired to portray UNIT soldiers in late August, exactly what and who were filmed inside Hodge House was unknown at press time.
Filming took place in Grange Gardens in Cardiff on September 20, beginning with the construction of the TARDIS prop. John Bishop and Bradley Walsh were seen at the location, confirming that new companion Dan and former companion Graham will appear in the centenary special. Jodie Whittaker, Mandip Gill, and director Jamie Magnus Stone were also at the Grange Gardens filming.
You can see more photos here: Welsh Rugby pics – Doctor Who Filming 200921 (huwevansimages.co.uk) ]
As always, thanks to the most valuable site I’ve found for Doctor Who Spoilers, cultbox.co.uk .