(REUTERS/Kevin Lamarque) The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) Behind them is a work titled "For Life in all Directions." The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge. Picture taken June 6, 2012.

(REUTERS/Kevin Lamarque) The gallery exhibits American contemporary crafts and decorative arts from the 19th to the 21st centuries. The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) The museum is home to one of the largest and most diverse collections of Native art and historical and cultural objects. The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque) Based on decades of cutting-edge research by Smithsonian scientists, the exhibits in the David H. Koch Hall of Human Origins tells the epic story of human evolution and how humans evolved over six million years in response to a changing world.

(REUTERS/Kevin Lamarque ) The two pieces seen here is part of Chinese artist Ai Weiwei's monumental outdoor work "Circle of Animals/Zodiac Heads." The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge.

(REUTERS/Kevin Lamarque ) The Freer houses one of the premier collections of Asian art. The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge. Picture taken June 19, 2012.

(REUTERS/Kevin Lamarque ) The enclosed courtyard with its elegant glass canopy, designed by world renowned architects Foster & Partners provides a distinctive, contemporary accent to the museums' Greek Revival building. The Smithsonian Institution, the world's largest museum and research complex, includes 19 museums and galleries. Most are free of charge. Picture taken June 25, 2012.