Free things to do with kids in San Mateo

Bayfront park with one of the Peninsula's few splash pads plus a big playground and picnic lawns right on the water. Flat Bay Trail access makes it stroller and balance-bike friendly.

A Park a Day Bay Area 'Top Pick': three climbing huts linked by a rope bridge, a big rope-climbing structure, 10 swings (4 of them baby swings) and a separate little-kids playground. Skate park next door for older siblings.

A Japanese tea garden, a miniature train on weekends, and a playground with restrooms.