Apart of the extensive collection of Sienese art, the museum also offers some great views over the city and a well heated environment (just in case your hotel isn't).
|The view from the first floor of the Pinacoteca Nazionale|
If you're after free folklore not art, visit Siena's San Francesco church instead. The cloister of the former monastery exhibits 50 presepi, Italy's famous Christmas cribs displaying the nativity scene (free entrance, daily from 3.30 pm- 7 pm until the February 2).
PINACOTECA NAZIONALE: FREE ENTRANCE DECEMBER 28, 2013
All state museums and archaeological sites will be free in Italy on the 28th (not in Siena? Ask the tourist office of the town you visit on the 28th which museums/sights belong to that category). In Siena the Pinacoteca is the only stately run museum and will stay open from 8.15 am to 7.15 pm. Also remember that you'll have free entrance to Italy's state museums on the day of your birthday. More information on Siena's museums on Map It Out's museum page.