As the primary international port for Fujian, particularly Zhangzhou and its hinterland, Xiamen became a center of China's tea trade, with hundreds of thousands of tons shipped yearly to Europe and the Americas. Its local dialect influenced a variety of translations of Chinese terms. Its principal exports during the period were tea, porcelain, and paper; it imported sugar, rice, cotton, and opium, as well as some manufactured goods. Xiamen was also a center of Protestant missionaries in China; the missions operated the city's two hospitals. The merchants of Xiamen were thought among the richest and most entrepreneurial and industrious in China, but the city was widely accounted the dirtiest city in China. Owing to local belief in feng shui, the streets were "as crooked as ram's horns" and averaged about in width to keep out sunlight and control public disturbances. Its population was estimated at 250,000 in the 1870s; by that point the island was largely barren and full of roughly 140 villages, with a total population around 400,000. European settlement in the port was concentrated on Gulangyu Island off Xiamen proper; it remains known for its colonial architecture.