Fallingwater (Bear Run, Pennsylvania) must be among the smallest of the most famous architectural masterpieces of the 20th century. If there is such a thing, this house built in 1936 for the Kaufmann family, is an intimate monument. You would not think that 2,500 sq ft of built-up area are enough to create a durable masterpiece. But Frank Lloyd Wright, the American genius who designed it (reportedly in a day), daringly floated out reinforced concrete terraces over the beautiful waterfall that was the centrepiece of the forested property. These terraces were pegged back into an exposed masonry core in the building that feels like it is emerging out of the hill. Wright thus achieved the effect that was closest to his heart &mdash the feeling that the building is growing &lsquoorganically&rsquo out of its setting. Walking through the house with oh-so-low ceilings (kept at places at 6 feet 4 inches, so the building itself sat horizontally in the landscape) you realise how architecture may dramatise nature the intimacy of the inside dramatises the grandeur of the outside immeasurably. Being on those terraces, meanwhile, is like being held aloft falling water in the extended &lsquopalm&rsquo of the building. Hence the name that Wright gave it. See www.fallingwater.org.