I’m a fan of The Crown but I don’t know much about when it starts filming next… however, I did find this on Wikipedia:
Filming for the series takes place at Elstree Studios in Borehamwood, Hertfordshire. It was estimated that 25% of the first season was filmed at Elstree Studios, with the remaining 75% filmed on location, with the season filmed over 152 days. Sets for private quarters, the interior of a private jet, the cabinet room, and the exterior of 10 Downing Street were built at Elstree Studios,[21][23] while Lancaster House, Wrotham Park and Wilton House were used for scenes to double as Buckingham Palace. Ely Cathedral stood in for Westminster Abbey, while filming in South Africa doubled as Kenya in the season.[21] Additional filming locations in the United Kingdom included, Eltham Palace, the Royal Naval College,[24] Goldsmiths’ Hall, Shoreham Airport, New Slains Castle,[25] Balmoral Castle, Cruden Bay, Lyceum Theatre, Loseley Park, Hatfield House,[23] The Historic Dockyard Chatham,[26] Southwark Cathedral, Ardverikie House, Englefield House, and Glenfeshie Estate.[27] Filming on the second season began in early October 2016.[22]
Source: https://en.wikipedia.org/wiki/The_Crown_(TV_series)
Thanks for the submission @a-steady-wish