San Diego Model Railroad Museum

Hands-on science galleries include Kid City and the giant-dome theater.

The Backyard gives kids five and under a protected space to climb, explore and learn about nature.

Outdoor museum cafe has a dedicated kids' menu next to Balboa Park sights.

Two play areas serve younger and older kids, with a sandbox, slides and picnic tables.

Kids can ride a short loop on the miniature railroad outside the zoo.

A 1910 carousel offers animal rides and a brass-ring game beside the zoo.