The National Arboretum in Washington, D.C., is just a few miles from the National Mall, with its famous monuments and museums like the National Air and Space Museum. Next time you're in D.C., consider a visit to the arboretum. It's a museum too, except all the exhibits are alive! With about 40 plant collections and gardens, it's a great place to take a hike, ride a bike, read a book under a tree, or just smell the flowers. To find out more, visit the arboretum's web site.