She had three apartments on New York's Fifth Avenue, all filled with treasures worth millions, not to mention a mansion in Connecticut and a house in California. But the enigmatic heiress Huguette Clark lived her last 20 years in a plainly decorated hospital room — even though she wasn't sick.

It's just one of many curiosities about Clark, the late heiress to the fortune of copper magnate Sen. Andrew Williams Clark. For years, even friends and family thought she was living on Fifth Avenue. Her lavish gifts to her nurse prompted a police investigation. And now, three years after her death at age 104, Clark's artwork and antiques are heading from her abandoned apartments to Christie's auction block.