Mostly known for crossing Paris, the Seine is an important transport route leading to the English Channel and, beyond it, the United Kingdom. The traffic on the river is dense and well organized, and huge barges transporting wheat or construction material cross the capital and intersect with cruise ships filled with tourists. Tugboats are responsible for putting the barges back on the right track as no less than 37 bridges and footbridges like the Alexandre III bridge span the Seine.