The three-story Richardsonian Romanesque Mason Block on the corner of Harris and Twelfth Street occupies one-quarter of the block and is one of the largest buildings in Fairhaven’s historic district. It was named for Allen C. Mason, the Tacoma investor who funded it, and designed by Tacoma architects James Pickles and Albert Sutton.

The design, with its rhythmic, round-arched arcade of windows on the third story, bears resemblance to Elmer H. Fisher’s Pioneer Building (1892) in Seattle’s Pioneer Square, yet predates that building by two years. In one of several remodels, a deep paneled frieze was added atop the ground story. The interior is finished in open gallery style with a three-story light well.

The Mason Block originally served as a commercial and professional building. Ground-floor businesses included clothing, hardware, groceries, and dry goods. Many tenants were in the medical professions, including doctors, dentists, and pharmacists, while the Railway Express occupied a street-front office. In the early days, the Cascade Club, a men’s club that hosted such distinguished visitors as William Howard Taft and Mark Twain, was located on the top floor. Later, the third floor was occupied by renters with housekeeping rooms.

Rehabilitated by developer Kenneth Imus in 1973 and renamed The Market Place, the building was the beginning of Fairhaven’s physical renaissance and its gradual transformation into a historic district. Its current owner renamed the building Sycamore Square.