Armory of the First Corps of Cadets
 Armory of the First Corps of Cadets is an historic armory at 97-105 Arlington Street and 130 Columbus Avenue in Boston Massachusetts.The late-Victorian armory was built in 1897 by William Gibbons Preston and added to the National Register of Historic Places in 1973.It is today known as the Park Plaza Castle and owned by the adjacent Boston Park Plaza Hotel & Towers which uses it as a banquet facility.