[MOD: moved to the "Travel Talks" forum, although this question is a little off-topic...]
Hello Ton Wijnen,
For Camellia, you probably want to check on Oshima (大島), a large island not far from Izu peninsula and Tokyo. The place is considered the capital for camellia in Japan, and they even have specific dishes cooked in camellia oil.
You can find
here a short abstract in English of a famous festival hold every year in winter and dedicated to those flowers. For the full story, it is unfortunately only
in Japanese, but with many pictures...
You can also check the
official web page in English for a list of attractions on the island, including a famous botanic garden dedicated, again, to camellia...
It is difficult to give you more precise details, but if you can find some breeders, it would probably be on Oshima...
Hope this bring some answers,
sanji