Three verified South Bay family options for Saturday, Aug. 15: KidStock at Pioneer Park in Mountain View, an outdoor screening of The Wild Robot at Vasona Lake in Los Gatos, and a rare open weekend at The Tech Interactive in San Jose during its maintenance closure.

If you've got kids and a South Bay Saturday to fill, August 15 gives you three genuinely different moves — a free morning festival, a free outdoor movie, and a museum that's supposed to be closed but isn't this weekend. Here's what each one actually is, and how to do it.

KidStock — Mountain View, free, morning. The city's long-running free kids' music festival runs 10 a.m. to 1 p.m. at Pioneer Park, 1146 Church St., a block off Castro Street in downtown Mountain View. Admission is free; it's walk-up, no RSVP. This is the low-stress option — grass, live kids' music, room to run — and downtown is right there when someone melts down and needs a snack. Do this one first: park in a downtown garage off Bryant or California, not on Church, and you can roll into lunch on Castro afterward.

Movie Nights in the Park: The Wild Robot — Los Gatos, free. Santa Clara County Parks screens the film at Vasona Lake County Park, 333 Blossom Hill Road, on Saturday night. The county listing puts the movie at sunset — roughly 8 p.m. in mid-August — running to about 10:45 p.m. Admission is free; parking is $6, cash or card at the gate. Pack blankets, low chairs, and a warm layer for after dark. Get there while there's still light to claim a flat spot near the screen; the lawn fills in once the sky goes. One honest caveat: if you're planning to arrive early for pre-movie activities, call the park first (408) 355-2240 — the county page confirms the film time but not a set start for anything before it.

The Tech Interactive — San Jose, one of two open weekends. The Tech is closed for annual maintenance August 10–28, but it's opening its doors for a special weekend on Aug. 15–16 (Saturday 10 a.m.–5 p.m.) at 201 S. Market St. downtown. Standard admission applies — $27 adults, $22 for kids, students and seniors, toddlers free — and access terms during the maintenance window aren't spelled out, so buy or check tickets at thetech.org before you drive in. It's the one paid option here, and the appeal is timing: a hands-on science museum that's otherwise dark for most of August.

If you've only got the afternoon: do KidStock in the morning, grab lunch downtown Mountain View, and drive down to Vasona for the movie at dusk — two free events, one tank of gas, no tickets required.