Château de la Tournelle

The Château de la Tournelle sits right along the Seine, marked by its long, low stone facade and the faint remains of a medieval tower built into the wall. It served as the primary entrance to Paris for French kings arriving by boat. In the fourteenth century, a massive iron chain was stretched from this tower across the river to the opposite bank, blocking all traffic. Travelers paid a toll to enter the city, and the chain stopped anyone from passing at night.