San Juan Historical Museum (405 Price St., Friday Harbor, 360/378-3949, www.sjmuseum.org [1], 10 a.m.–4 p.m. Thurs.–Sat. and 1–4 p.m. Sun. May–Sept., 1–4 p.m. Sat. in October, March, and April, closed the rest of the year, $2 adults, $1 ages 6–18, free for kids under 5). Housed in an 1890s farmhouse, the museum includes fascinating antiques, old photos, and historical artifacts, plus old farm equipment outside.
Also on the property are the first county jail, a log cabin, and other historic buildings.
Links:
[1] http://www.sjmuseum.org