 However, it is important to note that the channel between Ilhabela and São Sebastião had already been sailed by the Portuguese in 1502.All four cities relied on agriculture and fishing as its main economic activities for most of the 17th, 18th and 19th centuries, whereas São Sebastião served as a major sugar cane, coffea and tobacco production site.In the second half of the 20th century, the cities started to receive several tourists, mostly from São Paulo and nearby cities.