Converted from a single-family brownstone mansion, this Park Slope duplex still has much of its historic detailing on display–even in the bathroom. The home is located at 120 Prospect Park West, a stretch that faces Prospect Park and is known for impressive architecture built for wealthy Brooklynites. The modern-day asking price is $2.3 million for two levels of the building, one of which is the parlor floor, about 2,000 square feet awash in wood carvings and stained glass.