One of, if not the most important centres for justice and peace in the world, Peace Palace comprises the United Nations International Court of Justice, the Permanent Court of Arbitration, the Hague Academy of International Law and the Peace Palace Library. Although this is a working palace, which means most areas are closed to the public, there is, however, a visitors centre where those interested can learn more about the history of the palace and the role it plays today in international justice via a free audio tour. On rare occasions, the palace opens its doors to the public for guided tours, but it is advisable to check well in advance if any dates are available as they are few and far between. In any case, the impressive surrounding gardens and Neo-Renaissance buildings are definitely a must-see.

Rebuilt entirely after being destroyed during WWII, Château de Clervaux is among the Duchy's most notable attractions. It contains a fascinating UNESCO-listed photography exhibition, Edward Steichen's 'Family of Man', which takes its origins at MoMA (Museum of Modern Art in New York) and has now found a permanent home at Clervaux. The two other on-site museums, one displaying scale models of Luxembourg's castles, and another dedicated to the WWII Battle of the Ardennes (which resulted in the original castle's annihilation), are also worth exploring.

Founded in the 7th century by St Willibrord, the patron saint of Luxembourg, the Abbey of Echternach contains a fascinating scriptorium — once the most important in Medieval Europe — in its cellar, with manuscripts dating as far back as the 11th century. Part of the abbey complex, the Basilica of Saint Willibrord contains a crypt with the saint's holy remains. A dancing procession that draws visitors from all over the world (Saint Willibrord Pageant) is held in the town annually on Whit Tuesday.