The clue was: The listing broker for the 50-room mansion pictured above, which went under a sales agreement last week, also listed this Beacon Hill townhouse, which sold for $11,000,000 last April.
The answer is: What is 3 Louisburg Square? Tracy Campion is the listing broker for the 50-room Ames-Webster Mansion (pictured) and was also the listing broker on 3 Louisburg Square, which traded in April 2012 for $11 million.
· Back Bay Superbroker Tracy Campion's Greatest Hits [Curbed Boston]
· $11M for 3 Louisburg Square: Boston's 2nd-Biggest Deal of '12 [Curbed Boston]
· Boston's Newest Real Estate Parlor Game: the Ames-Webster [Curbed Boston]
· Our Games archive [Curbed Boston]