I stumbled upon information about Audley End House and Gardens (located in Saffron Walden, Essex) while browsing YouTube. It looks like the kind of place I'd love to visit, and would be an easy day trip from either London or Cambridge. https://www.english-heritage.org.uk/visit/places/audley-end-house-and-gardens/
The history section of the Audley End website is amazingly rich and detailed, and the "Things to See and Do" section looks like they offer a great range of visitor experiences.
On a lighter note, there's a butler called Mr. Lincoln who does a fabulous job on YouTube https://www.youtube.com/watch?v=6_dLqJBfPv4 I love how the closed caption says "Jolly Music" at the beginning of this Christmas video. This man could have his own TV series, as far as I'm concerned, LOL.