The Armory of the First Corps of Cadets is a historic armory at 97–105 Arlington Street and 130 Columbus Avenue in Boston, Massachusetts. The four-story granite structure was designed by William Gibbons Preston and built beginning in 1891 and finished in 1897. Due to political unrest during the period, the building was designed to withstand mob violence. Its most prominent feature is its six-story tower. It is built in the Romanesque Revival style. The buildings staircases are built by the Guastavino system, as are some tower vaults.