First of all, seafood, of course. You can eat a variety of seafood in Sanya. If you recommend Spring Garden seafood in Sanya, it is cheaper than the first market. If you go to the seaside store, you can see the sea view, but the price is a little more expensive!
Secondly, it's authentic Hainan cuisine. Hainan cuisine must eat Wenchang Chicken, as well as Jiaji Duck and Dong Goat. If you are in Sanya, you are recommended to go to Haiya Restaurant, which is very authentic!
Third, there are snacks in Sanya, such as refreshing coconut milk, barbecue and coconut water. Coconut cakes, etc., can be eaten in the first market, and the barbecue will come out at night.
Finally, it is a special product that Hainan can take away. Fruits (mango, papaya, sour beans, etc.) can be bought in the market. Coconut candy, coconut chips, yellow lantern peppers, coconut powder, Xinglong coffee, etc. can be bought in the shops in Sanya!