Wild rumpus: Wild things abound at the Contemporary Jewish Museum’s special Maurice Sendak exhibit, but mark Dec. 25 down. That’s a Target-sponsored Free Family Day, which means not just free admission, but a wild rumpus, DIY shadow puppet shows, movies and kid-friendly crafts too.

Funny flicks: Enjoy the Exploratorium’s annual Humorous Holiday Animation Film Festival Dec. 26-30, then browse the always wonderful exhibits. The flicks, including “Sour Death Balls,” which offers a quirky look at how people react to extremely sour candy, are included in the price of admission.

Floral Choo Choo: Check out the Golden Gate Express Garden Railway, a landscape of tiny trains, cable cars and streetcars that winds through San Francisco’s Conservatory of Flowers. It’s a celebration of recycling creativity, with cool new sound, visuals and aural effects too. Now through April 18; $2-$7.

Ride the Trains: Watching tiny trains is fun, but riding them is even better. Board the steam trains at Tilden Park’s Redwood Valley Railway and go for a jaunt through the Berkeley hills. Open weekends; $2.

Blast Off: Prep for a trip to Mars at the Lawrence Hall of Science’s new exhibit, “Facing Mars: Would You Survive the Journey?” Open daily; $6-$12.