If people ask about the best FREE place to go in Boston, there are two choices. I send history buffs to Old Ironsides and the museum at the Charlestown Navy Yard, but for more culturally minded folks... I send 'em to the library.
That's right. If you have a limited budget and can coordinate your schedule with one of the Art and Architecture tours given at the Boston Public Library's Copley Square library - go! The tour schedule is erratic, currently Monday at 2:30, Tuesday and Thursday at 6 pm, Friday and Saturday at 11 am. There are Sunday tours at 2 pm roughly October through May.
In 1885 Charles Follen McKim modelled this "palace for the people," on an Italian Renaissance pallazo, decorating it with the finest art American artists and sculptors could produce. The exterior was considered plain when first completed, and was compared to a mausoleum, a casket and an oversized cigar box but it was intended to complement rather than compete with other buildings surrounding Copley Square. His choice of materials from around the world - including marble from Italy, the Alps, Africa and 20 other different sources - was selected without worrying about his budget. It's forgotten now, but cost overruns on this project established a local tradition proudly continuing today in Boston's Big Dig.
Restoration work on two of the three major mural sequences in the building started in April 2002 and will continue for 18 months. Don't miss the third floor with John Singer Sargent's "Triumph of Religion," which he viewed as his masterwork, "bringing the Sistine Chapel to America" (a bit inflated opinion of himself, don't you think?). The murals have been difficult to appreciate underneath years of accumulated dirt, dust and grime but it's particularly interesting to compare areas where conservators have worked with unrestored sections.
The library is open most days from 9 am to 9 pm and people are welcome to investigate it on their own - but if at all possible take a tours to insure you don't miss any of the highlights and fully understand what you're seeing.