While visitors flock to the Smithsonian museums on the National Mall, they often miss the United States Botanic Garden, which is a real pity. A wide range of indoor and outdoor exhibits is offered - showcasing both common and rare species covering desert, rainforest, jungle and many other landscapes.
Established in 1820, this free attraction is well worth a visit and consists largely of a gorgeous enormous greenhouse located on the corner of the National Mall adjacent to the United States Capital and the National Museum of the American Indian.
The orchid garden is a particular standout.