we are renting a car for one day as we're staying in downtown DC and then have to get to Dulles that night. Cheaper to rent a car then any other way - so what are some day trips we might take, for a few hours out of DC??

Annapolis is nice, but it's in the opposite direction from IAD, as is Baltimore. Mount Vernon is easier with a car. If you want to get further afield, Charlottesville is within a couple of hours.

Thinking of kinda in the direction of Dulles (go somewhere and then IAD):

Leesburg has an old town -- shopping, restaurants, etc.
Manassas Battlefield, part of National Park Service
Marine Corps Museum, Triangle, VA
Middleburg, horsey-country
further out, Shenandoah National Park and various towns + nearby West Virginia, Fredericksburg, perhaps Gettysburg is too far
Woodlawn Plantation

If you go to Leesburg, stop by the visitor center and pick up a walking map of Waterford, which is an interesting historic area.

The museum in Old Town Manassas offers up a free walking tour brochure, too.

A bit further afield, but still just about an hour's drive from Dulles, Harper's Ferry is a nice day trip. Or Frederick MD has a ton of historic sites.

Depending on the time of year, you might also consider hiking in the Shenandoah area.

Or what about Luray Caverns? Or gambling at Charles Town Races and Slots?

excet the gambling...

we will probably stop at Leesburg...altho if we pick up the car early enough and the weather cooperates we might go out to Alexandria and then over to IAD.

You don't give us times to go by. You want to leave downtown by what time? What time is your flight from Dulles? Need extra time to return the car and take the shuttle to the terminal, of course. Exact times make a big difference. And how much driving are you willing to do? Harper's Ferry might indeed be doable with an early start, and a late night flight. Leesburg probably easier. Frederick doable. Luray a bit of a stretch, I think. You might look up directions to take the toll road Dulles Greenway (?) from the north to get into Dulles, avoiding the traffic on the Beltway leaving the DC area in the late afternoon/evening. There's also the National Air and Space Museum's Steven Udvar-Hazy Center, very close to Dulles (parking free after 4, I believe).

so time is not a big issue

thanks all.

So you're just staying at Dulles that night. Would have helped to include that info. Also a bit more as to your interests and how far you're willing to drive. A full day's drive from DC (not in DC) and then to Dulles potentially covers a huge amount of territory. If it's a weekday, still need to account for rush hour traffic, especially if needing to go back through DC to get to Dulles (e.g., if you go to Annapolis). If you want history and scenery, I'd consider Harper's Ferry, Winchester, Shenandoah Natl. Park, Frederick or Gettysburg. None of which would require cutting back through DC to get to Dulles, especially if you use the Greenway.

For natural beauty, +1 on Luray Cavens and Shenandoah National Park. There's a nice museum on the settlement of the Valley at Luray Caverns, so that coupled with a leisurely drive through scenic countryside makes for a great daytrip.

Manasas has a cute downtown for wandering, but not much to occupy your time.

There are number of wineries within an hour west of Dulles. Many are by appointment only, so you may want to plan ahead. I wish I could recommend which ones are best to visit... http://www.virginiawine.org/
More sophisticated shopping at Tysons Cornes, Dulles Center, and Fair Oaks.

And of course, the National Air and Space Museum's Udvar-Hazy Center.

What time of year are you going? Near future? or in the Spring, etc?

You can also use the car to simplify your sightseeing closer to the Beltway— for that matter, inside the District— rather than dealing with taxis or buses to get to places like

• National Cathedral
• National Arboretum
• Great Falls + Clara Barton Parkway
• Hillwood Museum
• Wolf Trap (if there is a show you're interested in)

Farther afield, the Udvar-Hazy Center, Mt. Vernon/Collingwood and the Marine Corps Museum have been mentioned, and you can hit 4-5 B-list places instead of driving 3 hours to rush through 2 A-list places. There's Roaches Run if you like birds. The NRA museum if you like guns. Claude Moore Colonial Farm if you like living history. It's not the season for golf now, but of course you need a car to get to any decent golf course in the area.

A C-List might include stops at the Air Force Memorial, Brookside Gardens, the Kreeger museum, the National Women's History Museum, or along the C&O Canal.

keeping this for future reference

we wound up not getting the car as a taxi was an equiv price and we wanted to spend another day in DC itself. But we're back often enough that these ideas are great, thanks.