In 963, Count Siegfried built a fortified castle on the Bock promontory, which was soon to become the cradle of the city. In the course of the centuries, on the western side, mighty ring walls were added, which, however, did not foil the Burgundians in their attempt to conquer the city in 1443. The best builder-engineers of the new masters (the Burgundians, the Spaniards, the French, the Austrians and the German Confederation) eventually turned the city into one of the most powerful emplacements in the world, the "Gibraltar of the North".
Its defences were bolstered by three fortified rings with 24 forts, 16 other strong defensive works and a unique 23 km long network of casemates: these could not only shelter thousands of soldiers and their horses, but also housed workshops, kitchens, bakeries, slaughter-houses etc. In 1867, after the declaration of neutrality,the military withdrew from the fortress and during the following 16 years 90% of the defences were demolished. In 1875, the superstructure of the Bock, a tremendous construction, was razed. However, it proved to be impossible to blow up the casemates, without also demolishing part of the city, so the entrances and the key connecting galleries were sealed. In spite of this, 17 kilometres of tunnels remain, often on different levels and tremendous stairways penetrateup to 40 metres inside the rock face. It goes without saying that these galleries functioned as shelters during the world wars, providing space for 35,000 people in case of air raids or shelling.
Small wonder that the fortifications and the historic old town enjoy world wide fame: in 1994 they were designated a UNESCO World Heritage Site.
Their origin goes back to 1644, when the Spaniards reinforced the medieval fortifications. Under the supervision of the Swiss fortress builder Isaac von Treybach, they built - among other defence works-the powerful Beck Bastion, named after Governor Baron Johann von Beck, a native of the city who had played a key role in the Wallenstein affair on the side of the Emperor. Initially this bastion was as high as the adjacent terraces on the right; it was raised to the present level of Constitution Square (the wall is 27 meters high) by Vauban in 1685.
In 1673 the Spaniards erected the so-called "Ravelin du Pate" to strengthen the defence of the Beck Bastion; this triangular construction is one of the few well-kept fortifications. Marshall de Vauban conferred the present shape to all the Petrusse fortifications and built the "Small Staircase". From 1728-29 the Austrians added the "Bourbon Lock" and the "Large Staircase" and in 1746 the casemates of the "Petrusse Battery" (54 gun emplacements). One century passed and the fortress was enlarged and reinforced: the second ring wasextended and the third started, so that Luxembourg became the "Gibraltar of the North".
By and by, the Petrusse fortifications fell into oblivion and neglect, as their strategic momentum limited itself to the valley. After the dismantling, stipulated by the 1867 London Treaty, they confined themselves to walling up the loopholes and most entrances.
Only in 1933 were the Petrusse casemates valorized again: on 26th July, the first visitors were able to visit them.
In its function as the city residence of the Grand-Ducal family, it is situated right in the core of the Old Town. Formerly the first town hall of the city occupied the site of the present palace; destroyed by a gunpowder explosion (1554), the town hall was rebuilt 20 years later. In the middle of the 18th century the former City Scales were added as an extension, whereas the Chamber of Deputies was built as an annex in 1859.
Since 1890 the main building has been the Grand Ducal Palace. From 1992 to 1995 it was restored thoroughly.
Closed for transformation works from 1 March 2011 !
The transformation of "Dräi Eechelen" (Three Acorns), the nick name for Fort Thüngen, into a Museum has required major renovation work. Partially hidden underground following the demolition in 1867 and covered with abundant vegetation, the fort and its surroundings are today the subject of excavation, restoration and rebuilding work with the aim of returning them to their former glory, whilst integrating a contemporary museum space. The Museum, including the underground gallery, forms an integral part of the Vauban Circuit. The museography to come will depict an attractive combination of the fortification legacy in Luxembourg, the history of the Grand Duchy, and the different aspects of its national identity.
The castle remains closed from 9th January until 14th May because of restoration works.
Probably built in the 10th century, Bourscheid chateau was first mentioned in a document in 1095. In the 14th and 15th centuries, it was greatly enlarged and a fortification wall was built, flanked by six Gothic towers. The ruins of the chateau abandoned in the 19th century were bought by the State and opened to the public. The ruins of the chateau above the Sûre valley are illuminated.
The maison de Stolzembourg, a superb Gothic manor house built in 1348, houses a small museum which traces the history of the chateau and the lords of Bourscheid; it is used as the setting of the Bourscheid cultural weeks.
Floodlit every day until midnight.
Vianden The chateau of the counts of Vianden was built between the 11th and the 14th century on the foundations of a Roman fort and a Carolingian refuge. The chateau was inherited after 1417 to the House of Orange-Nassau. Superbly restored since 1977, this chateau and palace is one of the largest and finest feudal residences of the Romanesque and Gothic periods in Europe.
2 old castles (11th century) with the rebuilt “Maison de Créhange” stand on a rocky crag high above the beautiful and romantic valley of the White Ernz.
2012 
