The six-story building at 194 Beacon Street in Back Bay dates from 1862 and was converted to condos in 1974. It houses only four and this 3-BR, 3.5-BA triplex is one of them. It just hit the rental market for $12,500 a month. It's got 3,214 interior square feet but that's nothing: outside and in the garage there are another 3,000 or so, including what the listing calls a "a substantial Japanese garden." Done.
· Listing: 194 Beacon Street, #2 [Zillow]