Two and a half hours from the Mall lies the Brandywine Valley,bordering Pennsylvania's Chester and Delaware counties, a setting of rolling hills, farmland, winding country roads and old stone houses that offers the weekend driver both autumnal and local color.

The valley is best known for the Battle of Brandywine, fought on the river's banks, for the three generations of Wyeths who painted its hills and for the legacy of du Pont mansions and estates that dot its countryside.

A good place to start exploring is at BRANDYWINE BATTLEFIELD STATE PARK, where on the eve of the 1777 battle, General George Washington and his aide, the Marquis de la Fayette, set up their headquarters in the residences of two prominent Quakers, Benjamin Ring and Gideon Gilpin. Restored and filled with 18th-century antiques, both houses are open to visitors. Near the GILPIN HOUSE is a large sycamore tree, where Lafayette is said to have had his battle wounds dressed. At the park's visitor center, exhibits and a slide show tell the story of Washington's unsuccessful campaign to stop the British from taking Philadelphia.

Heading east from the park along U.S. 1, you'll find the restored JOHN CHAD HOUSE, home of the farmer, ferryman and tavern-owner who also gave his name to the town of Chadds Ford. Built around 1726, the stone house is a fine example of 18th-century country architecture, with a two- story spring house alongside, which once served as a 19th- century schoolhouse.

Nearby is the BARNS-BRINTON HOUSE, a restored 18th- century tavern immortalized in Andrew Wyeth's painting "Tenant Farmer." Named after two of its former owners -- William Barns and James Brinton -- the house has a fine exterior of Flemish bond brickwork and a Revolutionary War history -- it was pillaged by Hessian Lieutenant General Wilhelm von Knyphausen's troops on their march to the Brandywine. Unfortunately, when U.S. 1 was moved in 1938, it ended up north of the building, so the tavern now has its back to the road it faced for more than 200 years.

Heading north from the battlefield, you'll come upon the CHRISTIAN C. SANDERSON MUSEUM, which houses a small but unique collection of Brandywine memorabilia. Sanderson lived in the Benjamin Ring house from 1906 to 1922 and devoted most of his life to the idea of making the battlefield a state park.

After the Brandywine River Museum, Hagley Museum, Longwood Gardens and Winterthur, there's NEMOURS, the country estate of Alfred I. du Pont, named after the family's home in north-central France.

In 1909, du Pont built a 77-room chateau after the manner of Louis XVI and filled it with antiques, tapestries and art. The 300 acres of grounds include a front-garden vista of a third of a mile.

Continuing along U.S. 1, you'll find two more traditional museums and one rather mouldy one.

The PHILLIPS MUSHROOM MUSEUM, is on Phillips Place in the town of Kennett Square, which once housed British troops and has now become the self-proclaimed mushroom capital of the world. The museum's exhibits and films detail mushroom lore from growing the fungus to cooking it.

The FRANKLIN MINT MUSEUM, farther up U.S. 1, houses goods manufactured by the well-known concern that sells silver trinkets of all sorts.

Finally, the HILLENDALE MUSEUM, has three-dimensional dioramas and globes and a self-guided recorded tour detailing four centuries of North American exploration, focusing on how geography affected settlement on the continent.

TO GET THERE

Take I-95 north to U.S. 202 north, then north on U.S. 1 to Chadds Ford.

WHAT TO SEE

BRANDYWINE BATTLEFIELD STATE PARK -- On U.S. 1 at Chadds Ford. Historic buildings are open 9 to 5 Monday to Saturday, noon to 5 Sundays; visitor center closes at 4:30. The park is open from 9 to dusk. Free. 215/459-3342

JOHN CHADD HOUSE -- Route 100, 1/4-mile north of U.S. 1. Open by appointment. Adults: $1, under 12 and over 65, 50 cents. 215/388- 7376

BARNS-BRINTON HOUSE -- U.S. 1, 1/4-mile west of Chadds Ford. Open by appointment. Adults: $1, under 12 and over 65, 50 cents. 215/388-7376

CHRISTIAN C. SANDERSON MUSEUM -- Route 100, a hundred yards north of U.S. 1. Open Saturday and Sunday 1 to 5. No admission, but donation requested.

BRANDYWINE RIVER MUSEUM -- U.S. 1, west of Route 100. Open daily 9:30 to 4:30. Adults $1.75, children 6 to 12 and adults over 65, $1. 215/459-1900.

DELAWARE ART MUSEUM -- 2301 Kentmere Parkway, Wilmington, Delaware. Open Monday through Saturday 10 to 5, Sunday 1 to 5. Free. 301/571-9590.

BRANDYWINE RIVER -- Canoe and inner tube rentals: Wilderness Canoe Trips, Inc., 302/654-2227; Northbrook Canoe Co., 215/793- 2279.

HAGLEY MUSEUM -- Route 141, east of Route 100, Wilmington. Open Tuesday through Saturday 9:30 to 4:30, Sundays 1 to 5. Closed Mondays. Adults $2.50, students through college and adults over 62, $2, children under 14 free. Tours take 3 to 4 hours. 302/658-2400.

WINTERTHUR -- Route 52, north of Route 141. Open Tuesdays through Saturdays 10 to 4, Sundays and holiday Mondays noon to 4. Admissions range from $2 for a garden tour to $7.50 for a reserved house tour. 302/654-1548.

LONGWOOD GARDENS -- U.S. 1, west of Route 52. Open every day, outdoor gardens 9 to 6, conservatory 10 to 5. Separate fee for house and gardens. 215/388-6741.

NEMOURS -- Route 141, east of Route 100. Open Tuesdays through Saturdays with tours at 9, 11, 1 and 3. Sundays tours at 11, 1 and 3. Reservations suggested. Admission $4. 302/651-6912.

PHILLIPS MUSHROOM MUSEUM -- U.S. 1, Kennett Square. Open daily. Free. 215/388-6082.

FRANKLIN MINT MUSEUM -- U.S. 1, west of Route 452. Open Tuesday through Saturday 9:30 to 4:30, Sundays 1 to 4:30. Free. 215/459-6168.

HILLENDALE MUSEUM -- Route 52, south of U.S. 1. Open Monday through Saturday 9:30 to 1:30. Adultss$3, students up to 12th grade, $1.50 (only children who have completed the sixth grade will be admitted to the museum.) (215) 388-7393.