I sort of answered this here.
But, if I have to only choose one destination only, I am going to Korea not only because @whaichi’s photos always touch something within me, but also because three weeks is a long time during which I could not only make lots of Observations but also I could gorge myself on bulgogi and bibimbap. (I am food motivated.)
If I can break the three weeks up though, two in Korea, followed by a week recovering and watching the parade of visitors to @danly’s garden still. Heaven.