Eltham Palace

Eltham Palace is what happens when a medieval royal residence meets a 1930s millionaire couple with exceptional taste and no interest in restraint. The great hall dates from the 1470s, built for Edward IV with one of the finest hammerbeam roofs in England. Henry VIII grew up here as a boy, playing in the gardens and hunting in the surrounding deer park. But after the English Civil War, the palace was abandoned and the great hall was used as a barn.

In 1933, Stephen and Virginia Courtauld — he was the brother of art collector Samuel Courtauld — took a 99-year lease on the ruins and commissioned architects Seely & Paget to build a spectacular Art Deco home grafted onto the medieval great hall. The result is one of the most extraordinary houses in London: you walk from a fifteenth-century hammerbeam roof directly into a 1930s entrance hall by Swedish designer Rolf Engströmer, with light flooding through a glazed dome onto blackbean wood veneer and figurative marquetry panels.

The Courtaulds were obsessed with technology. The house had underfloor heating in every bedroom and bathroom, a centralised vacuum cleaning system, an internal telephone exchange, and a loudspeaker system — all in the 1930s. Virginia's circular bedroom and gold-leaf bathroom were designed by Italian architect Piero Malacrida. They also kept a pet ring-tailed lemur named Mah-Jongg, who had his own heated quarters on the upper floor.

The Courtaulds left in 1944, and the house fell into military and institutional use before English Heritage took it over in 1995. The 19 acres of gardens, including a moat that pre-dates the palace, have been beautifully restored. It remains one of London's greatest hidden gems — a place most Londoners have never heard of.