Luxembourg city is situated on a number of hills separated by steep valleys containing rivers. One of its most important bridges is this viaduct built between 1859 and 1861, before the demolition of Luxembourg`s fortress. It crosses the Petrusse Valley at a height of about 100 feet and has 24 arches. The bridge is over 300 yards long and offers fine views of the city. At the northern end of the bridge is the National Monument of Luxembourg Solidarity.