there is so much mystery behind it (The DaVinci Code for example).
The da Vinci code is fictional and has no historical basis, if you weren't aware.
On-topic, there's a lot which I like... Japan, Taiwan, Ireland, the celtic parts of the United Kingdom, pretty much all of Scandinavia... Romania as well, and perhaps Liechtenstein. The Netherlands are nice, too, and I'm sure I'm forgetting quite a bunch here. I can't really decide on a specific country :S (Also, why is Vatican City in the poll but not Italy? o.o)