I visited the Jeju Osulloc Tea Museum with my family and I would say it's definitely worth a visit! You get to learn more about the company's history and origins which was very cool. But the two main highlights are 1. the treats and teas you can buy at the gift shop and 2. the green tea field! They have such a wide variety of teas and tea flavored snacks, not to mention some Jeju souvenirs as well. I would also recommend getting some food at the cafe as they do have some items that are exclusive to the Jeju Osulloc Museum. The green tea fields were so pretty and vast, makes for a really pretty photo when the sky is clear which was when I went!