I&;ve been there twice. The architectural style there is very unique and the environment is quiet. They are all former foreign or foreign trade venues, so the architectural style is different (a bit like that in Qingdao, Shandong Province at that time) and very exotic. There are churches, parks, schools and complete facilities on the island. Many newcomers take wedding photos there. Last time I went there, I saw six or seven couples taking photos. Half a day is enough to walk around Shamian Island. By the way, I suggest you can go to Sacred Heart Cathedral in Shishi, which is not far from Shamian. It is also a good place to punch in the tourist card.