Mariner's House, an important example of the type of Greek Revival commercial building once common throughout New England ports, provided temperance boarding for seamen. The polygonal cupola with its cornice and brackets enlivens the traditional granite storefront, flat stone lintels, and brick entablature at the roofline. Mariner's House is one of the earliest surviving buildings by Gridley J. F. Bryant, who designed an extraordinarily large and varied group of buildings during his long career in Boston. Built by the Boston Port and Seaman's Aid Society, Mariner's House provided inexpensive room and board. Other amenities included a reading room and a store supplied with goods made by the families of seamen so that they could earn money while their men were at sea. Still used as a boardinghouse for seamen, the interior was recently extensively renovated.