Frank Lloyd Wright is an American icon - it's most famous modern architect, and probably it's most prolific - over 400 buildings in a 60-year career. But his most revealing constructions are his houses, revolutionary in their open plan design, and conceived as an expression of Wright's philosophy of a perfect harmony between man and nature: 'organic architecture' as he called it. Wright's houses also embody an ideal for living based on calmness and order, but his own life was characterised by public scandal, financial chaos and personal tragedy.