Otter River State Park is located in Winchendon, in north central MA proximate to the NH border. The park was certainly lovely, facilities clean and my stay pleasant. Sites were a bit small. The hiking trails in and around the camp trail were nice, but not overly remarkable. Don’t recall there being a ton to do in and around the neighboring towns. Really, this is a good, low-key spot for families looking to spend a couple days out of the city. It’s about a 1 1/2 hour drive from Boston. Kids can play safely and bike throughout the grounds.