The Bock- and Petruss casemates are the largest casemates in the world and are Luxembourg's top attraction, with more then 105.000 visitors in 2010.
The Bock rock is considered as the cradle of the city of Luxembourg. In 963 the count Siegfried established his castle there.
In 963 the count Siegfried from the Ardennes acquired the Bock rock. This cliff jutting out over the Alzette river played an important role for Siegfried’s military strategy. As it was surrounded by the Alzette valley on three sides and only accessible from the western side, it was easily defensible.
Protected by this cliff you can find the Bock casemates and the archaeological crypt, which reports on the construction of the castle of the first Luxembourgian counts.
These underground, man made galleries were registered on the UNESCO World Heritage List in 1994. They are the unique witnesses of the glorious past of this legendary fortress town. For four centuries, Luxembourg was occupied by foreign sovereigns and the best engineers of the new rulers (Burgundies, Spanish, French, Austrians, German Confederation) transformed the town to one of the strongest fortresses in the world.
The defence of the citadel was insured by three surrounding walls with 24 forts and 16 other fortifications, as well as with an extraordinary network of 23km of underground casemates.
The first Petrusse casemates were constructed in 1644, under the Spanish sovereignty modernising the medieval fortifications. Then, at the beginning of the 18th century, the Austrians perfected the defence system of the Petrusse valley.
The Bock casemates, dug by the Austrians in 1745/46, had a surface of 1500m2 and could shelter a garrison of 1500 and their equipment, as well as 50 canons.
All these constructions made the town to one of the most important fortresses in Europe, deserving the title of “the Gibraltar of the North”.
In 1875, the superstructure of the Bock, a very important fortress, was razed to the ground. Only one tower remained.
After de dismantling of the fortress in 1867, some parts of the casemates were destructed and reduced to 17km.
Today, the Bock- and Petrusse casemates are accessible for visitors, with or without a guide.
Sources: www.lcto.lu, www.ont.lu