In the mid-17th century the west and north of the Netherlands developed a unique and highly efficient public transport system along the waterways. The basic ingredient was the barge. Towed by horses, these narrow, covered boats sailed on regular routes at regular times. An extensive network of tow barges across the flat, watery countryside provided a simple and cheap method of transport from one place to another. In the 19th century barges became obsolete as roads and railways were built.