Hi,
Here is a new letter box in Central Maryland just outside of DC

Lake Artemesia Flower Letterbox clues
Berwyn Heights, Maryland
Branchview/Ballew Avenue (parking)
Sept. 9, 2000
twograysquirrels

This is near the University of Maryland

Highlighted by a 38-acre lake, this park boasts an aquatic garden, good fishing (including a handicapped accessible fishing pier), and over two miles of hiker-biker trails. No vehicles are permitted on park grounds. Enter via hiker-biker trails at the 5200 block of Calvert Road, College Park, or at Osage Street and Swathmore Court in Berwyn Heights.

In the fall and early winter you can see lots of migrating ducks at this lake. Lots of nice dragonflies in the summer. Who would have thought to find this in the middle of the city.