In the 17th century, Louis XIV had the medieval upper part of the town (the former Longwy-Haut) destroyed in order to rebuild in its place a new town structure which was to serve as a defensive link on the North-East front. Based on a hexagonal layout, Longwy was built by the Marquis de Vauban, foremost military architect of his time, as the ideal Baroque fortified city: church, arsenal, barracks, fountains, houses grouped around a square, and the whole surrounded by a massive star-shaped defensive wall with six bastions. A monumental main gate (the so-called French Gate) and four of the six bastions have been preserved to this day. Two bastions contain munitions and powder depots, the other two house the cruciform casemates whose noteworthy building shape is exceptional in Vaubans oeuvre.