The Port of Helsinki is Finland's main port, specialized in unitized cargo services for Finnish companies engaged in foreign trade. The strength of Helsinki's port lies in regular and frequent ship traffic combined with efficient stevedoring operations. Vuosaari Harbour serves container and roro traffic. South Harbour and West Harbour serve roro traffic transported by passenger ships. Helsinki is also the busiest passenger port in Finland, with diverse services to Tallinn, Stockholm, Travemünde, Rostock, Gdynia and St. Petersburg. During summer time international cruise ships make almost 300 visits and bring over 420 000 tourists to Helsinki.