The four biggest ports of Latvia are located in Riga, Ventspils, Liepāja and Skulte. Most transit traffic uses these and half the cargo is crude oil and oil products. Free port of Ventspils is one of the busiest ports in the Baltic states. Apart from road and railway connections, Ventspils is also linked to oil extraction fields and transportation routes of Russian Federation via system of two pipelines from Polotsk, Belarus.