In May 1939 the travel writer HV Morton wrote:
I was boasting to a man at Sevenoaks that I had seen most of Kent's finest houses: Chevening, Penshurst, Hever and Knole.
"But you haven't seen Ightham Mote?" he asked. "You can't be in Kent and fail to see Ightham Mote. If you don't see it, you'll always regret it!"
The house dates to the 1320's and is a lovely moated manor house.
The house was the subject of extensive renovation by the National Trust since its acquisition in 1989 (£10 million+ according to Wikipedia), The programme ended in 2004. It was also the subject of a Time Team special - and the trust will happily sell you a copy.
The house though was open long before the Trust got their hands on it. Morton visited in 1939 when the house was opened on Friday afternoons and found "quite a small number crowd" waiting.
In 1953 was purchased by the American Charles Henry Robinson who made many urgent repairs and left it to the Trust.