She grew up with a Rodin and Rubens in the home. Now, Huguette Clark, at 103 years old, owns a $100+ million Santa Barbara oceanfront mansion which has been unoccupied since 1963. Her 52-acre New Canaan estate and a 15,000-sq.-ft. Fifth Avenue apartment are empty, too. What is known about Ms. Clark is that her controversial father, whose fortunes in copper rivalled Rockefeller wealth, once owned one of the grandest American collections of European paintings. His cache by masters from Corot to Degas went to the Corcoran Gallery. In 2003, Huguette sold a Renoir for $23.5 million...