By Noralyn Dudt WASHINGTON DC, the U.S. capital abounds in monuments, memorials, museums, and galleries. When the city was first designed in 1790, the planner whom George Washington commissioned, Pierre L'Enfant envisioned a grand capital of wide avenues, public squares and inspiring buildings in what was then a district of hills, forests, marshes, and plantations. The centerpiece of L'Enfant's plan was a great "public walk." That's now what we call our National Mall. Stretching for 2 miles, from Capitol Hill to the Potomac River, this "public walk" is a wide, straight strands of grass and trees. The Smithsonian museums flank both sides and war memorials are embedded among the famous monuments that memorialize Washington, Lincoln and Jefferson. With 21 museums including the National Zoological Park, the Smithsonian institution is the world's largest museum, education and research complex. In one of the most visited museums—the Mus