Sylt is connected to the German mainland by the Hindenburgdamm causeway with a railway line on top. The passenger trains connect Westerland to Niebull or Klanxbull. Hindenburgdamm is an 11 km-long causeway opened for rail traffic in 1927. Every day, more than 100 trains pass over the causeway, 50 of those ferrying cars (there is no road link to Sylt). Each year, the railway ferries more than 450,000 vehicles over the causeway.