FOR THE KIDS : Last-Minute Adventure Before Class Bell Sounds : There’s still time to catch the tail end of ‘The World of Peter Rabbit’ at Santa Barbara’s Natural History Museum.

They’re nearly gone, those last few days of summer vacation. The start of the new school year is ever so close for most kids, but there is still a little time left for an adventure or two.

Where to go?

You can catch the tail end of “The World of Peter Rabbit” at the Natural History Museum in Santa Barbara. The exhibit ends Sept. 5, and even if you’ve already seen it, it’s worth seeing twice.

Everyone knows Beatrix Potter’s story of Peter Rabbit, who disobeys his mother and sneaks into old Mr. McGregor’s garden, only to find himself in big trouble.

The museum’s auditorium has been transformed into Mr. McGregor’s garden--all from a rabbit’s eye view, of course, so the cabbages are five feet around, the carrot tops nine feet tall and the watering can is so large that children can crawl inside, just as Peter did to escape the old farmer.

Remember the “Tale of Mrs. Tiggy-Winkle”? The kindly old hedgehog in bonnet and apron is there too, laundering the clothes of little forest creatures. Children can also see the dollhouse ransacked by the mischievous mice in “The Tale of Two Bad Mice.” They can also explore a child-size house with vegetables on the table, dishes in the cupboard and aprons and bonnets on the hooks.

In an adjacent room, children can fish in Jeremy Fisher’s pond (the bait and fish have Velcro stitched on them). They can hold live rabbits and watch a family of mice scamper about in a mouse house. They can also dress up as Peter Rabbit or one of his pals, but they might be upstaged by an adult-sized Peter who roams the auditorium giving hugs.

The exhibit isn’t just for kids. Potter, who created Peter Rabbit about a hundred years ago, led an extraordinary life, and it’s all part of the exhibit.

Born in 1866 to a strict upper-middle-class family in England, she was raised in near isolation by nannies and tutors. She turned to art, stories and nature for fun.

She was so restricted by her parents that she kept a diary in code from the time she was 14 until she was 30. It wasn’t until 1958 that someone finally cracked it.

The code is part of the museum’s exhibit. It’s been programmed into a computer, and using an electronic mouse, kids can try to crack the jumbled letters and decipher a message.

(The museum is at 2559 Puesta del Sol Road, Santa Barbara. Admission is $5 for adults, $4 for seniors and teen-agers, $3 for children 2 to 12, children under 2 free. For information: 682-4711.)

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Looking for a way to cool off? Lake Piru east of Fillmore allows public swimming during the summer until Oct. 1. In fact, it’s the only freshwater spot in the county where you can take a dip.

Last week the water was a toasty 78 degrees, and it’s very likely to stay fairly warm through September, according to manager Doug West. But you can’t just dive in wherever you feel like it.

Swimmers are restricted to a roped-off area at the north end of the lake, about two miles from the entrance. The spot is about 100 yards wide and 50 yards out into the water--far enough to be over your head.

You can swim daily from sunup to sunset, but a lifeguard is only on duty on weekends and major holidays from 10 a.m. to 6 p.m.

Oh, and expect some company. West said that on a busy day, 200 to 300 swimmers take the plunge.

(Lake Piru is east of Fillmore off California 126. Cost per day is $5 per vehicle, plus another $5 if you bring a boat. For information: 521-1500.)

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Here’s another way to beat the heat. Conejo Valley Ice Skating Center in Newbury Park expands its public skating hours during the summer to give kids a chance to cruise the ice.

The hours, in effect until Sept. 11, are: Monday through Friday, 12:30 to 3 p.m.; Saturday and Sunday from 1:30 to 3:30 p.m., and Wednesday, Friday and Saturday nights from 8 to 10 p.m.

Admission is $6.25 for adults and $5 for kids 12 and under. Skate rental is $2.

Here’s a tip from rink employee Mike Howard: Dress warmly, even though it may be a scorcher outside, because the temperature inside is only about 50 degrees. Gloves or mittens are a good idea.

Here’s another tip: Watch for the opening of a new ice rink in Simi Valley about the end of September.

(Conejo Valley Ice Skating Center is at 510 N. Ventu Park Road. For information: 498-6669.

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If you haven’t made it to the Ventura County Fair by now, it’s not too late. In fact, the rodeo will be going on at the fairgrounds Friday, Saturday and Sunday. (Fair admission gets you into the rodeo free.)

This is traditional rodeo stuff--calf-roping, steer-wrestling, bull-riding, barrel racing--all put on by the Professional Rodeo Cowboys’ Assn. It’s doing five shows this year: Friday at 7 p.m., and Saturday and Sunday, 2 and 7 p.m.

But not all of it will be standard ride ‘em cowboy fare. A new act this year sounds intriguing. Pro cowboy Tommy Lucia will be showing off the dancing skills of his trained horse, In His Glory, a swayback horse he rescued from an uncertain fate. Lucia also has a monkey he has trained to ride a sheep dog while the dog herds sheep into a pen.

(The fair runs from 11 a.m. to midnight daily, through Sunday. For information: 648-3376)

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Those child-size Alphabet Soup Puppets will be back on stage Saturday at the Camarillo Art Center. Puppeteer Arla Crane will do a show based on Chumash and other American Indian folk tales. Then she’ll run a puppet workshop in which the children will make a puppet from the play.

The show-workshop (for ages 4 to 8 years) begins at 11 a.m. at the center, 3150 Ponderosa Drive. Admission is $3 at the door. Adults are free. For information: 445-7061.