Stately and elegant, they stand near the James River, between Richmond and Willamsuburg, where they've watched centuries pass. They're an attraction that few visitors can resist - the James River Plantations.

These sturdy mansions are some of the finest country manor houses remanining in America. In early times, tobacco made them rich and the same river that tied them economically to England also brought news of the social and literally scenes in London. So the James River Valley was the undisputed cultural center of the colonies. It was also the "cradle of the Republic, for presidents and statesmen were born in these homes.

Both the Revolutionary and Civil Wars dealth blows to the plantations. The tobacco empire wilted after the Revolution and never regained its former strength. Instead, other areas of the country began culativating tobacco. And many of the surviving James River plantations switched to less glamourous crops such as barley, corn, sybeans, cattle, and sheep.

Today another cash crop has been added to the list. It's the visitors who come and pay anywhere from 50 cents to $2.50 to see these handsome homes of history.

Counting the plantations on the other side of the river, off State Route 10, and one down past Williamsburg off U.S. 60 there are 10 river plantations that accept visitors at some time during the year.

A few are open year-around, but some can be seen only during Historic Garden Week, which is April 22, to 30 this year. More than 200 of the state's finest homes and gardens will be included in the tour.

The first of the river plantations out of Richmond is SHIRLEY, about 25 miles away. The present house was begun in 1723, and the ninth generation of its original owners live there now. It was in the parlor that "Light-Horse" Harry Lee married Anne Hill Carter. Their son, Robert E. Lee, received some of his schooling here. Hours are 9 to 5 daily; admission is $2 for adults, $1 for students, and 75 cents for children. 804/795-2385.

BERKELEY PLANTATION, a few miles away, was built by the Harrison family in 1726 and is the ancestral home of a signer of the Declaration of Independence and two presidents. Walking shoes are a necessity here, for after a tour of the home you can walk down a lane leading to Harrison's Landing, the site of the first Thanksgiving in America. A re-creation of that day is held here every November. Hours are 9 to 5 daily; admission is $2.50, half-price for children 6 to 12. 804/795-2453.

Right next door to Berkeley is WESTOVER, built around 1730 by William Byrd II, the founder of Richmond. The home itself is open only during Historic Garden Week. The rest of the year, you can wander through the grounds and sit on one of the benches that overlook the James River. Hours are 9 to 6 daily April 25 to 29; admission $1.50 for house and grounds; admission to the grounds only is $1. 804/829-2882 and 829-2547.

BELLE AIR PLANTATION, built around 1670, is one of the oldest frame dwellings in the country. It is said to have one of the finest Jacobean staircases in America and is decorated with 18th century furnishings. It, too, is open only during Historic Garden Week (10 to 5, April 25 to 29; admission $2). The rest of the year it is open by appointment for group tours only. 804/829-2431.

After several years of restoration, SHERWOOD FOREST opened to the public early last year. It was built between 1720 and 1730, and purchased in 1842 by Presdient John Tyler. His grandson and family live there now, and among the furnishing are many original Tyler items. Hours are 9 to 5 daily; admission is $2.50 for adults and $1.50 for children under 12. 804/829-5377.

About 6 miles southeast of Williamsburg on U.S. 60 is CARTER'S GROVE, often called "the most beautiful house in America." The estate was originally owned by Robert Carter, one of Virginia's wealthiest and most influential men. His grandson, Carter Burwell, built the home between 1750 and 1753. Today the home is operated by the Colonial Williamsburg Foundation and contains many beautiful and priceless furnishings. Open daily March 1 to November 30 and during Christmas week; hours are 9 to 5; admission is $2 for adults and $1 for children. 804/229-6883.

Crossing over to the other side of the James River is the Jamestown Ferry, which connects State Route 31 between Williamsburg and Surry. It operates year-round on Friday, Saturday, and Sunday from 10:30 a.m. to 7 p.m.; the fare is 80 cents for automobiles and 20 cents for pedestrians and bicycles.

Just across the river is SMITH'S FORT PLANTATION, built on land given to John Rolfe in 1614 by Chief Powhatan when Rolfe married Pocahontas, Powhatan's daughter. The home was built in 1652 by Thomas Warren and is one of the earliest of the river plantations. Its name comes from the nearby site of a fort built by Captain John Smith in 1609 to defend Jamestown. Open daily for Histroic Garden Week; open Wednesday through Sunday, from May through September 30, hours are 10 to 5; admission is $1.50 for adults and $1 for students and children. 804/866-2506.

Southeast of Smith's Fort is BACON'S CASTLE, built in 1655. In 1676, 100 years before the Revolutionary War, it was occupied by a group of rebels protesting the tyrannical rule of Royal Governor William Berkeley. The rebels held the home only four months, but the name of their leaders, Nathaniel Bacon, lingers on today. Open Wednesday through Sunday from Historic Garden Week through September 30; hours are 10 to 5; admission is $1.50 for adults and $1 for students. 804/357-5976.

Close by is CHIPPOKES PLANTATION STATE PARK. A number of structures on the grounds reflect plantation life from the 17th through the 20th centuries. Open Tuesday through Sunday, from Memorial Day through Labor Day; hours are 10 to 6; admission is 50 cents for adults and 25 cents for children. 804/294-3625.

Along the 55-mile stretch between Surry and Richmond is BRANDON PLANTATION, which sits on a land grant dating back to 1616. Brandon is said to represent the longest continuous agricultural enterprise in the United States. The home, which was designed by Thomas Jefferson, is open only during Historic Garden Week (daily, April 26 to 29; admission $2). But the rest of the year you can wander through the vast grounds, open 9 to 5:30 daily; admission is $1. 804/866-2416. FINDING YOUR WAY THERE

From Washington, take I-95 or U.S. 1 to Richmond, then State Route 197 (Laburnum Avenue) skirting the capital to State Route 5.

A free guidebook giving dates and detailed information is available from Historic Garden Week headquarters, 12 E. Franklin St., Richmond, Va., 23219. 804/644-7776.

The Virginia State Travel Service also offers guidebooks, brochures on the various plantations, maps and other information. Its Washington office is at 906 17th St. NW. 293-5350.