John Hancock Tower

200 Clarendon, known as the John Hancock Tower until 2015, is the tallest building in Boston at 241 meters (60 floors). Designed by architects I. M. Pei and Henry N. Cobb, the modern skyscraper stands out for its monolithic, minimalist architecture. A striking feature is its continuous, bluish mirrored glass facade, which reflects its surroundings on clear days and visually blends the tower into the cityscape. The name goes back to the John Hancock insurance company, whose offices were housed in the building for many years. Two older buildings nearby, also named after the insurer, are symbolically carried on in the new tower's facade.

The tower's history, however, is also marked by considerable technical challenges. After its completion, panes of the double-glazed facade came loose in strong winds, leading to closures of the surrounding area and earning the building the mocking nickname "Plywood Palace." The problem was only solved after working with the Massachusetts Institute of Technology, when the entire facade was replaced with tempered safety glass. In addition, the structure had to be reinforced with extra steel, and the pronounced swaying on the upper floors was dampened by heavy tuned mass dampers. Despite these early difficulties, the building received the American Institute of Architects' Twenty-five Year Award in 2011.