What type of events are on the Common Saturday after the parade?
The Londonderry Town Common is full of fun events for families. The event is not your typical flea market, craft show, or collection of food vendors. You will find two types of booths, the not for profit organizations of Londonderry, New Hampshire typically sell a product, often times food. This is a big fundraising event for many local organizations in town. Local companies are required to have a game or event for kids, they are not allowed to solicit sales in a overt fashion.
You may even see a dog or two 
OHD answer pup
