Grand Back Bay duplex includes greenhouse, mantels from 1860s

The bones of the 2,150-square-foot, six-room Unit 1 duplex in the brownstone at 129 Beacon Street in Back Bay date from the early 1860s. Touches from that era remain, including the mantels over the fireplaces.

The 3-BR, 2.5-BA, which begins on the building’s parlor level, also includes space for a greenhouse (right next to the patio).

The spread last sold in 1994 for the rough equivalent of $655,000 in today’s dollars. Yours now through Keller Williams for $2,500,000.