A red-brick Elizabethan manor stranded among 1930s suburban semis: Eastbury is a small miracle of survival. Built around 1573 by the wealthy merchant Clement Sysley, it has the H-plan, the mullioned windows, and the twin staircase turrets of a Tudor merchant's country house — and it is one of very few of its kind left anywhere in London.
Inside, the wall paintings on the upper floor are remarkable: late 16th-century trompe-l'oeil panels of architectural fantasies, half-faded but still legible. The walled garden has been restored to its Tudor layout. Run by the National Trust in partnership with the local council; check the website for opening days, as access is more limited than for the Trust's bigger properties. Free for Trust members.