Watch World's Most Extreme Homes Season 1 Episode 12 Online

Architect Alex Michaelis spotted a great plot in London's fashionable Notting Hill district, but planning restrictions limited him from building anything higher than the 6-foot high garden wall. So Michaelis dug a 20-foot pit and built the home in the crater. Mandy and Michael Millsap enjoy a tremendous view from the deck of their South African game lodge home. Kasteel Amstenrade has been in the d'Ansembourg family for over two centuries, and the decor in the 64-plus room castle has hardly changed in that time.