Boston’s Institute of Contemporary Art, with its striking cantilever overlooking Boston Harbor, may be the most architecturally significant building to be built in the Hub in a generation. “Four decades ago the completion of a City Hall in Brutalist concrete sent the city’s cultural guardians into a panic. Since then, with a few exceptions like the John Hancock Tower, the city’s architectural aspirations could generally be summed up in one word: brick.” But the ICA, which stands in a largely undeveloped area at the moment, will eventually be more than a stand-alone monument to creativity: “Viewed through a maze of new buildings, the structure could wield the force of a wonderful surprise.”