Look Park, Northampton MA

Look Park is beautiful. You'll have to pay a $4 fee per car as you enter. Then you can park wherever you like. There are a LOT of activities here.

Water pad: instead of a wading pool, they've created a concrete "pad" with motion detectors which are linked up to a couple dozen different fountains which randomly turn off and on. Though it seems like kids would fall, they rarely do. Plenty of benches and chaise lounges encircle the pad. Many are under small pavillions providing shade. Bathing suit activity. Fenced in with two points of entry/egress. Free.
Petting zoo: Corn from a little machine costs 50 cents. A path leads through a wooded area lined with animal exhibits. Bald Eagles, sheep, owls, mountain goats, peacocks, chickens, more. The animals are well cared for, but the area is not too fancy.

Three playgrounds (small, large, and extra large):

The small playground is located right outside the petting zoo (convenient distraction!) and near the train station.

The large playground is on the other side of the park, near a pavillion, a stream, and some restrooms.

The extra large playground is right next to the water pad and restrooms and has a toddler structure, two other large structures, and swings.

River running by for rock throwing.

Train: Each ticket is about $2, the ride is cute - 10 minutes maybe? The kids LOVE it.
Paddle Boats: The rental fee is not ideal, but the ride is fun.
Picnic Areas with BBQ (rental fee), several pavillions for rent.
Restrooms are located near the water pad and are ok.