This formidable citadel designed by Vauban is home to the monument of National Solidarity. From the top of the citadel, which is known as the "Plateau of the Holy Spirit", enjoy magnificent views of the Pétrusse and Alzette valleys, as well as over to the Rham Plateau and the lower town of the Grund district and the Church of St-Jean. Much of the plateau is occupied by the legal district, which includes the Law Courts and Constitutional Courts.