Breakheart is a nice oasis of a park just a stone's throw from the garish glitz of Route 1. It provides some good, basic mountain biking for people who live nearby, and are looking for something less demanding and technical than Lynn Woods. A great place for beginners, or for a quick biking fix for locals. It's pretty quiet during the week, but can get busy with families and hikers. There's swimming in one of the two ponds in the park. There are some paved roads, most of the singletrack is moderate or easy; but you can expect the rocks and roots that make trail riding in New England what it is.
Directions:
Take the Lynn Fells exit off Route 1; drive about 3/4 mile; entrance is marked on the right.