Located less than 20 miles from the university town of Princeton in New Jersey and 70 miles from New York, this 1960 house was designed by architect Jules Gregory with an undulating double-conoid roof that appears to hover in mid air. Gregory built the house for himself with the use of many natural materials, using fieldstone from the property for fireplaces and walls, and Pacific Northwest white fir and pine from Colorado for the framing and wood paneling throughout the interior. The 1,664 sq ft residence includes four bedrooms, two bathrooms and a sunken living room. It has stayed true to its original design, with only a few updates to the kitchen and bathrooms. Set amidst a woodland landscape on a 10-acre estate, the property includes a footbridge over a seasonal stream leading to additional guest quarters. It is on the market for $999,000 (c.£671,000).