THERE YOU ARE, en route home from Williamsburg, and the kids are getting restless. As a matter of fact, you could do with a break yourself. History is all very well, but after a while it comes time to forget fact and get into fantasy.

A relaxing European tour awaits you at Busch Gardens, only four miles east of Williamsburg, and when you're through with that, new delights lie up the road at Kings Dominion, 20 miles north of Richmond. The theme parks just opened full time for the season -- seven days a week, morning til night -- and you'll never visit Italy or the Effel Tower cheaper.

The big news at Busch Gardens is that the Old Country is adding a new country this year. The theme park that brought us England, Scotland, France and Germany is going to make it possible for us to visit "Italy" without the pain of paying for an airline ticket, hotel room, etc. Probably by late June we'll be able to walk acrossd the 300-foot bridge spanning the Rhine River and step onto a tiered plaza in Italy. The date isn't certain. Remember, Rome wasn't built in a day.

The Busch people are sticklers for authenticity and they have big plans for their recreated bit of Italy. The hillside village they are constructing is architecturally correct right down to the doorhandles and employes the distinctive red-tile roofs and covered walkways of the mother country. The 100 stone columns which support the buildings have all been specially carved and painstakingly worked over to give the effect of antiquity. Old brick was covered with plaster and then beaten to make the walls look as if they were crumbling. Guests can sip their wine in what appears to be the ruins of ancient temples.

The focal point of the new country is the plaza where shows will be performed all day on an open-air stage. There'll be Italian folk songs and dances and light Italian opera with tunes so familiar that the audience can join in. The featured group will be Renaissance Flagmen of Sansepolcro, whose act revolves around some eye-catching business with five-foot flags.

Watch your diet before you drop in at Busch Gardens Italy, because on all sides you will be offered delights like ravioli, cannelloni, fettucini Alfredo and Italian ice creams. You'll be able to watch these traditional dishes being made in a glassed-in display kitchen. If all this is too filling, you can settle for lighter fare at a wine and cheese shop.

If you're after amusement, you can drop in at Leonardo's Garden of Inventions, where everything is keyed to the remarkably ahead-of-his-time work of the 15th-century artist and inventor DaVinci. Three new rides will open here this summer, including a balloon ride for small children. Everybody can get in on the fun of the orbiting, whirling thrill ride designed in Europe and a contraption based on the theory of the swinging pendulum. All this takes place in the center of a handsome landscaped garden.

You can, of course, make the whole Europeand tour at Busch Gardens. The bridges into enchantewd foreign lands spill you off in England by Big Ben and the Globe Theatre where Mark Wilson will be performing his magic shows this summer. Or in France, where the Chinese Acrobats of Taiwan will be entertaining strollers. La Jolie Plume, the circus put on my macawas and cocktails, will be playing a show with feathered performers entitled "Around the World in 80 Days." Or in Germany where at Oktoberfest, German dancers will be recreating Munieh with the Polka and other Old World dances. And New France's Trader's Village still offers Le Scoot with a 50-foot plunge toward a buzz saw at the end for kicks.

It's all included in the $9.95 one-price, one-day admission ticket (13.75 for two days, but starting at 5 p.m. the first day), for ages 3 and up. There is also a "nighttime special special" rate of $6.95 effective after 5 p.m. from June 21 through Aug. 24, and on Aug. 30-31.

Kings Dominion has also been busy over the winter figuring out, this time, how to scare us all witless. The Haunted River, which opened May 24, combines the fine points of a river boat trip with a visit to a haunted house. When I toured it, they were adding the finishing touches, and I made the journey on foot since the boat had not yet been installed. I can attest that frightening things happen inside the Haunted River.

A combination of dummies, animation and real actors keeps you constantly off base. Just as you have dismissed the vampire rocking on the porch as a mecahnical creature, she turns up live around the bend. Spanish moss dangles ghost-like fingers in your face, mummies rise from jugs, you barely escape the collapse of a large pile of heavy boxes which tumble just as you have passed. A hugh spider squirts some sort of venom at you and alligators made from papier mache yawn.

Most striking of all is the fleeting glimpse of the skeletons' dinner party, a large group of partygoers sitting around in their bones, wearing costumes of the 17th century. They sip wine and toy with their food, apparently unaware anything is lacking. While you think this over, the boat suddenly drops 30 feet over a waterfall as a finale.

Other attractions include the Lost World's Land of Dooz, a journey through the home of the little folk who live there, and a Time Shaft centrifugal force ride that flattens its customers against the side of the conveyance.

For all this you pay the old one-price rate of $9.95 for all rides and attractions, or select one of two other alternatives. (The alternative price option has long been successful at Disney World, though the all-inclusive rate has been a relatively new development.)

Since early last month, visitors have been able to choose either an adult or children's ticket book at $7.95 (the kiddies get two extra tickets), or a general admission ticket for $6.95. If you pay the top price, you will also get (for the first time) the safari through the wild animal preserve. In former years this cost an extra $1.50 (it is now an "A" coupon in the ticket books).

Park managers think the best ticket value for teen-agers is still $9.95, with unlimited use of the rides. For small folk under 52 inches, the children's ticket book might be the best buy. If you'd rather die than climb aboard the Rebel Yell, Kings Dominion's roller coaster, and would prefer to stroll by the lagoon beneath the Eiffel Tower and shop while the kids ride the Log Flume or the steam train, general admission tickets make sense. The nonrider can still enjoy the free attractions like the air show and the animal petting zoo.

Route 95 will lead you straight home, but then you would miss one of the most overlooked attractions on the Richmond-Washington road. It's a large change of mood and you'll have to get off the thruway, but while you're passing this way you should visit Kenmore, the home of George Washington's sister, Betty, who married Coloniel Fielding Lewis.

An interesting diorama begins the tour, which finishes in the kitchen with tea and gingerbread. Even the children will be glad you took the time.

Look up when you go through this house. Clement Conger, White House curator, calls the decorative plaster ceilings and overmantles of Kenmore, built in 1752, the finest in the western hemisphere, according to W. Vernon Edenfield, director. Don't miss the overmantle in the drawing room, suggested by George Washington and drawn from Aesop's fable of the Fox and the Crow. This is one house in which we know for sure Washington slept -- rather often actually -- and legend says he came here after his engagement with Cornwallis and flung himself across the guest bed, fully dressed even to his muddy boots.

The house right now is in its summer dress with the side panels of the curtains and all the rugs put away. It is cool, pleasant and beautiful, and smells of the same gingerbread that Mary Washington served to Lafayette when he came calling at her nearby home in 1784. The gingerbread served in the kitchen to visitors is the same recipe. The exact ingredients are a secret.

Except -- psst -- that Dromedary bought the recipe some years back and the packaged mix you buy in the supermarket is the very same one.

P.S. Visit the gift shop on the way out. It is usually attractive.