Van Saun Park is probably one of the best state parks in Bergen County. It has a ton of things a family, or even a couple, can do together. The main attraction is probably the zoo, where there are lots of animals to see, and depending on the season you may even see some alligators. There's an old-style train ride you can go on that encircles the buffalo den, and also goes into a pretend mine shaft. And as is expected of a park, there's tons of open space, and plenty of picnic tables to eat at. Note, however, that the main attractions aren't free - you must pay to get in.