Before Europeans arrived, Māori either walked or used watercraft on rivers or along the coasts. The road network of New Zealand has its origins in these tracks and paths used by Māori and later by Europeans in their early travels through New Zealand. Several major Māori tracks were known, such as the western coastal track was used along the whole length of the North Island, and the track on the East Coast, which left the coast near Castlepoint and rejoined it near Napier. In the South Island, another major track existed down the east coast with tributary tracks following streams up to the mountain passes to the West Coast. Mountains, swamp, and dense bush made inland routes tricky to traverse, and early settlers also made use of beaches as roads, for walking, riding horses, and herding sheep. Many farms had access via beaches only, and beaches were used as runways for planes. Some beaches are still used by planes, for example at Okarito and on the west coast of Stewart Island.