From their website:
Located in San Diego's beautiful Balboa Park, the Timken Museum of Art houses the world-class Putnam Foundation Collection of European old masters American art, and Russian icons.
Artworks in the collection range from 13th-century altarpieces through 18th-century portraits to 19th-century still lifes. Represented are the works of Dutch, Flemish, French, and Italian painters, including Rembrandt, Rubens, Petrus Christus, Fragonard, Jacques-Louis David, and Veronese, as well as American artists such as John Singleton Copley and Eastman Johnson.
Admission to the Timken Museum of Art is always free.