In episode two, Piers and Caroline's journey starts in an ancient Pine forest just outside Madrid, where the architect's brief was to weave this contemporary house among the trees themselves. Clad entirely in basalt and glass, the building reflects the surrounding forest whilst the interior contrasts with incredibly bright primary colours.Their next stop takes them to the USA and to two houses built in the Catskill Mountains in New York State. The first is a very modern tree house, an upside down three-bedroom home with the living space at the top and bedrooms on the bottom, offering an incredible view over the trees themselves. Nestled into the woods, the house is built on a plot the size of a caravan and clad entirely in glass. The second house is equally modern in design. Arriving by helicopter, Caroline and Piers wander around this high-tech, high-spec imposing structure that was constructed much like a sky scraper. With a double height open-plan living area providing panoramic views of the forest, the structure seems to hang into the forest clearing below.Piers and Caroline's final stop takes them to Piha in New Zealand, to a house that is built within an indigenous forest of native Pohutukawa trees. Navigating very strict environmental laws, this wooden-cladded and glass-roofed house mimics the branches of the surrounding trees, while its huge sliding glass walls open up completely to allow the surrounding forest to become an intrinsic part of the house itself.