Back in 2008, this duplex penthouse on North Moore Street was listed for $17.9M, lingered on the market, was chopped all the way down to $11.25M before disappearing from the market in March 2009. Three years later the listing is back, asking an eye-popping $21.5M. Of course, the sprawling, 6,900-square-foot loft is located on one of downtown's most coveted streets, but it's not like that's changed since the apartment—which occupies the top floor of two adjacent buildings—was last on the market. Plus, old listing photos show interiors that look very similar to the current ones, making a pricey gut renovation seem unlikely. So, the pricing remains a mystery, but the general desirability of the place does not, as it boasts four bedrooms, 3.5 baths, a Lutron lighting control system, a Savant automated entertainment system, and a huge, well-equipped, 2,300-square-foot roof terrace.