Found along the lush banks of the Napa River, deep twinkling pools beckon to anyone with a weakness for cool water on a hot summer's day.

Most of the best swimming spots on the river aren't marked by signs. They're not advertised in any brochure or Web site. And often the only hint that a luscious pool lies nearby is a few cars parked on the roadside.

Entry to these wild oases is always free, but usually by invitation only.

Someone brings you -- usually a friend, or a relative -- and so the secret of Napa Valley's river pools has been passed along from generation to generation.

For many people, returning to their favorite swimming hole provides a healthy dose of natural beauty and nostalgia.

Carlos Badilla introduced his wife and children -- 7 and 9 years old -- to his river refuge under the Zinfandel Bridge as they drove back to Napa after an outing to Calistoga on an uncomfortably warm Saturday afternoon.

"On the way home the kids were buggin' and buggin' about wanting to go swimming somewhere," Badilla said. "I said 'All right I'll take you swimming.' Jump in. Enjoy yourself. Relax."

A few feet away Badilla's son and daughter, pant legs rolled high, waded into the knee-deep water to cool off and pick up river stones.

"It's a place I always came to cool off since we're away from the oceans and lakes," said Badilla a 32-year-old painter who grew up in Napa.

Badilla's uncle first brought him and some cousins to "Zinfandel" on a summer day back in 1984. To this day he thinks the pool has a magical glow.

His wife, Reina Badilla, agreed as she took in the shade and sun-splashed pool, the sandy cliffs, and the rambling greenery surrounding the Zinfandel Bridge.

"This is beautiful," exclaimed Reina, who grew up in Riverside. "You don't see this stuff (in Riverside)."

Part of the fun over the years became discovering new secret hideaways within his old river haunt, Badilla said.

"The coolest part is you can sit behind this waterfall and watch the cascade in front of you," Badilla said.

Along with contemplative moments, Badilla admitted enjoying some wild times at the Zinfandel spot too, he said.

"People come down here to get drunk and crazy," he said. "Nobody says nothing.

"Everybody's had their share of those days," he added with a chuckle.

Discovering paradise

While going down to the river is a trip down memory lane for Badilla and other adult locals, young people first encountering a swimming hole often can't help but feel they're the first to discover that piece of Eden.

"Not that many people come here," said Linden Fowler, 17. "I think its kind of a new thing."

On a 100-plus-degree Saturday, Fowler and buddies Rick Rose, Tyler Lotridge and Ted LeMasters -- all Napa High students -- had taken to the cliff overlooking one of the most popular swimming holes within the Napa River Ecological Reserve off of Yountville Cross Road.

There they perfected their swan dives and other stunts using the rope swing whose single tether hangs from a thick oak branch. A "new" rope swing was strung up six years ago, according to 16-year-old Lotridge.

Grasping the rope's triangular handle so tight their knuckles turned white, the boys took turns sailing off the sandy cliff over the shore to drop themselves into a pool that's apparently 12 to 15 feet deep.

They were most intent on mastering their back-flips.

"I was pretty scared at first, to tell you the truth. I hesitated and then I just decided to go for it," said Rose, 17, who was making his swimming hole debut. "You have to make sure you get all the way around, otherwise you hit your head."

Other stunts included swinging two at a time on the rope -- a risky venture at best considering the single tether has been worn down by an unknown number of people over an unknown number of years.

But the teens waved off any suggestion they might be putting themselves in harm's way.

The rope was sturdy, the weather hot, and they were having fun.

The quartet anticipated this trip would mark the first of many to the Yountville watering hole. Lotridge's uncle introduced him to the rope-swing cliff as a kid. Now a teen, he's sharing his "secret spot" with friends. The boys were greeted by several more who strolled up the trail laden with towels, sunscreen and snacks.

"I'd rather go here than be in a pool," LeMasters remarked.

"It's not crowded and its natural," Lotridge added.

As young people like these make their first swimming hole memories, others return to the river havens to stay in touch with their youth.

"It brings back a lot of great memories. I would bug my cousins to come out here a lot. I've been coming here since I was Joe's age," said Joe Bedolla, pointing to his 9-year-old son Joe Jr., a shorter and skinnier replica of his dad. Both practiced diving over and over into the Zinfandel pool from the surrounding rocks. The water shoes they both wore allowed them to scramble quickly up and down the slippery stones.

The two tried turning a stretch of water-caressed rocks into a makeshift waterslide using their yellow "slip-and-slide" strip, but the rocks proved too rough for riding.

Inner tubes are better, the elder Bedolla concluded.

"Especially on a hot day you get to swim and stuff here," exclaimed Joe Jr., breathing hard after a round of diving. The fourth-grader at Salvador Elementary School added:

"It gets me out of chores and stuff."

But sometimes there are river chores, the elder Bedolla reminded his son.

"We try to keep it clean. We pick up other people's garbage and beer cans," he said with a shrug. "I don't want anyone to have to tell us we can't come back."