Whether in Seoul for a month, a week, or even just a day on a layover, one place not to miss is Changdeok-gung Palace and its wooded 'Huwon' garden. 'Garden' is somewhat of a misnomer, as the pavilion-and-pond-dotted-grounds encompass 78 acres of forest-covered hills, a veritable arboretum including specimens that are centuries old.

Most people in Seoul still refer to this old royal enclave, established in the early 1400's, as 'Biwon'--the 'Secret Garden.' Through the centuries, it's also been called the 'Inner Garden,' and the 'Forbidden Garden.' Today, this UNESCO world heritage site is open to all.

Visitors are allowed to wander among the halls of the palace compound, but to protect its ecology and architecture, you must join a guided tour group to visit Huwon. (Available in English twice a day, in addition to Korean, Japanese, and Chinese.) As was the case for royalty in the past, the grounds today are an oasis from the city. Traffic and skyscrapers are a world away; magpies chat in the green canopy; curved tiled-roofs hint at past intrigues...

Closed on Mondays.
For more info:
http://eng.cdg.go.kr/main/main.htm