Erected in 1896, the Guaranty Building was one of the earliest high-rise office buildings in Buffalo, an architectural wonder in ruddy terra cotta designed by the Father of the Skyscraper himself, Louis Sullivan. With breathtaking vertical lines, exquisite Art Nouveau ornamentation all over the faAade, and a design that is a near-perfect embodiment of the modernist credo form follows function, the building was for many years the headquarters of the ”’Buffalo Prudential Insurance Company”’ (hence its alternate name, the Prudential Building) and was named a National Historic Landmark in 1975. There’s an interpretive center in the northeast corner of the lobby with exhibits on Sullivan and his partner, Dankmar Adler, the building’s history and architecture, and the history of its current occupant, the law firm of ”’Hodgson Russ”’, now the oldest continually operating business in Buffalo. Guided tours are also offered by appointment.