We visited Sandringham a few weeks ago and thought I might share a few photos.
It is about a 2 to 2.5 hour drive from London.
The website will give a more detailed history than I could:
This is where the Royal family spend Christmas time.
There isn't a huge number of rooms that you see, but they are beautiful and completely furnished.
Unfortunately you can't take pictures inside.
There is also a small museum to visit.
The gardens are very nice to walk around.