With the summer sun high overhead, it’s the perfect time cool off with a splash. Often tucked away in some of nature’s most beautiful areas, swimming holes are hidden gems that offer a day full of adventure, fun and lazy moments soaking in the sun—the perfect escape for adventurous couples looking to beat the heat in a memorable way.

Picking the perfect swimming hole isn’t as easy as driving to the nearest river, though; you have to know what you’re looking for.

"The holy trinity of swimming-hole quality is height, depth and privacy," says Pancho Doll, author of Day Trips with a Splash, a pocket guide to the best swimming holes from Maine to San Diego (www.running-water.com). Here are his tips for finding the perfect swimming hole:

Height of adjacent rock walls. Find a spot that has a sense of enclosure or architectural feel.

Depth of water. Shallow spots don’t count; make sure it’s deep enough to take a plunge in.

Privacy. A good swimming hole should be secluded and private. "You don’t want to take your date to a shallow river basin next to the state highway," Doll says. "Rather, aim for a trip that takes some knee muscle to get to. It makes a shared experience more memorable than a drive-up spot."

Dry Spot. Finally, make sure it has a flat structure to dry off on. "A good swimming hole needs a beach or smooth rock large enough for you and your companion to stretch out on."

Plunging into a swimming hole is fun, but don’t let an avoidable injury ruin your good time. Keep the following in mind before you take the plunge:

Don’t dive in head first. You never know what could be lurking underneath; an old tree stump, rock or deceivingly shallow area could spell disaster.

Don’t jump extremely high heights. It’s tempting to test your fears, but stick to jumping from lower levels. You can’t be certain of any swimming hole’s depth.

Wear water shoes. Not only do they provide extra grip for scaling rocks, but they also protect your feet from broken glass and other sharp objects.

Leave the alcohol at home. Most swimming-hole related injuries, and even deaths, are the result of an inebriated person making the wrong decision. Save the cold beer for relaxing at home after your adventure.

For a list of over 900 swimming holes across the country, check out www.swimmingholes.org to find the best swimming hole near you.