So, how do you engage young adults in the “Israel in the Gardens” celebration?

How about sending them scrambling around San Francisco, scavenging for clues and competing for prizes?

This isn’t child’s play. Rather, the new scavenger hunt — tied into the “Israel in the Gardens” festivities — is aimed at getting Jews ages 21 to 45 involved in the celebration of Israeli culture.

Event organizer Shiri Gamon, hostess at The Cellar’s “Second Saturday” for Jewish singles and the volunteer coordinator for the scavenger hunt, said she hopes the scavenger will draw even more participation in the event marking Israel’s 58th birthday.

“The idea behind the scavenger hunt is to combine the Jewish history of San Francisco with the history of Israel, using different riddles and questions, where all young adults regardless of their background can mix and mingle,” she said.

“I think ‘Israel in the Gardens’ is an amazing experience, [but] the focus tends to be on families with younger children, and the young adults get lost in the shuffle.

“This is a way to get the young adults more involved in the day and, in the process, they learn about the history of their country, the history of the city, enjoy the sun and meet new people.”

Early discussions about planning a scavenger hunt entered Gamon’s radar over a year ago. She joined forces with a small group of volunteers to research, plan and organize the activity.

The hunt will begin in the morning at a to-be-determined location near Yerba Buena Gardens. Groups of five to 10 people will travel the city, digital camera in hand, seeking out destinations of Jewish cultural relevance based on clues found at each location.

Participants will return to Yerba Beuna Gardens in time for the headliner concert, and a winner will be announced at the Ruby Skye after-party.

For more sedentary types, Tzavta (the Israel Center’s young adult program) has planned a “young adult zone” at Jillians at the Metreon, where people can “hang out and shmooze” between 11 a.m. and 5 p.m.

And in the evening, those with energy to burn can go to Ruby Skye, at 420 Mason St., where they can dance, nosh on free hors d’oeuvres and partake of the no-host bar. Typically, Gamon said, “as the park clears out after the headliner concert everyone walks together” to Ruby Skye to begin the after-party.

Although Gamon is keeping mum on details of her research that resulted in chosen scavenger hunt locations (no need to give away helpful hints in advance!), she spoke enthusiastically about the interesting findings they unearthed when looking for culturally relevant locations throughout the city. She and her team of volunteers visited local Jewish institutions to review documents and learn about the early Jewish history of San Francisco.

“It’s amazing how much Jewish history there is in the city outside of the museums and the buildings that we’re all familiar with” as Jewish landmarks, she said.

“One of my favorite things about San Francisco is just walking through the city, now that I have this knowledge. So much of the city has started with very Jewish roots and Jewish families. At the scavenger hunt, we’ll be traveling back in time to catch up on our history.”

There will be up to three dozen scavenger hunt locations, accessible by foot, cab or public transportation. Participating groups probably won’t cross paths, as each will be traveling to different locations. The hunt will require team members to decipher clues, find locations, document them using their digital cameras and then find clues for the next location.

Participants will be able to sign up in advance as individuals or in groups; the fee is $10 per person. Event details are still being finalized and will be posted on the “Israel in the Gardens” Web site, www.israelcentersf.org/israelinthegardens/2006.

The Israel in the Gardens Young Adult Scavenger Hunt is sponsored by Camp Tawonga, the Cellar, Hadassah L’Atid, Tzavta of the Israel Center, YAD, and Young Adult Community of Congregation Emanu-El.

The Ruby Skye after-party for ages 21-plus is free, and the first 100 partygoers can get a free drink at the bar.