Highgate: Prince Charles' estate

While I was visiting my sister-in-law over the Thanksgivings weekend, I looked through two books by or about Prince Charles.  One was about his views on architecture and included several of his loose, sketch-like water colors.  The other book was about his gardens and landscaping at Highgate.  He turned it into a very beautiful spot incorporating some existing features and having built some beautiful fences and gateways of stumps, some exceedingly tasteful pergolas and other outbuildings (temples?), and  a system to cleanse sewage. He uses lots of compost and is organic in his aproach. He's also interested in rare trees and shrubs.  I don't really follow the comings and goings of the royal family but I'm glad the one of them is a plantsman and artist.