Best free things to do in Springfield (Massachusetts)?

There are four museums near downtown in the area known as the Quadrangle Drive;  a brand new Dr. Seusse museum opens next week-end!  The admission to all the museums is pretty reasonable, I think $10 for all of them.  The oldest operational planetarium is in the science museum;  the art museum is of surprising quality.  

Naismith Memorial Basketball Hall of Fame is pricey, but world class.

The armory museum is a national parks museum, if you are interested in the subject matter it is very engaging, a tad niche, however.

During the summer there is outdoor free music on Thursday nights in downtown;  also on Wed. a local brewery (White Lion) sponsors pop-up events with food and drinks for sale at very reasonable prices.  Nice way to meet youngish professionals.

Forest Park (Massachusetts) is a large park designed by the same landscape architect as Central Park in NYC (Olmstead).  Admission is $2;  it is safe (I walk my dog there alone all the time) and very lovely.  

There are lots of great restaurants;  The Student Prince/Fort is a local landmark serving German food and has a great bar;  Chef Wayne's Big Mamouhas authentic Cajun and is BYOB;  Red Rose Pizzeria is terrific and affordable, and Adolphos is great for more upscale Italian.  Max's tavern is a terrific steak house (a bit pricey) by the Hall of Fame Avenue, and there is a Pizzeria Uno by the Hall of Fame with a huge outdoor courtyard and free live music all summer.

Most of Springfield is pretty rough, so be aware ( I live one town over). There is a Dr. Seuss National Memorial Sculpture Garden. STCC has a Springfield Armory and the Naismith Memorial Basketball Hall of Fame (http://www.hoophall.com/hours-ticket-info/).  If you can travel a bit outside of Springfield there is some very good hiking. (10 min away) Mt Tom http://berkshirehiking.com/hikes/mt_tom_ma.html, (20 min away) and The Notch( http://www.mass.gov/eea/agencies/dcr/massparks/region-west/mount-holyoke-range-state-park.html).

Northampton (Massachusetts) is a short ride away ( half hour from Springfield). Its an eclectic college town with great restaurants, shops and art. 

The Berkshires are a short ride away with swimming holes, hiking, butterfly conservatories (http://www.magicwings.com/)