Out in Vienna is a great botanical garden. We actually went there to see some cherry blossoms because I wanted to avoid the crowds and traffic in DC.
There's a good sized parking lot right out front of the welcome center, so you shouldn't have an issue with parking.
Inside the welcome center are brochures, etc, and several aquariums with local wildlife. Plenty of snakes, some frogs/toads, and some turtles.
This little guy was super friendly.
There are a few bridges going over the creeks that feed into the large pond in the center of the garden.
Gorgeous flowers everywhere.
There is a cute gazebo in the center of the pond.
Now he's smiling (even if he is out of focus)!
There is a Korean garden with a cool wooden wall, this bell pavilion, and some Korean totem poles (I'm sure they have a correct name but they looked just like Native American totem poles).
We really had a great time and would love to go back sometime for a picnic.
9750 Meadowlark Gardens Court Vienna, VA 22182