Luxembourg - The Pétrusse CasematesTweet
The Pétrusse Casemates date back to 1644 when the Spanish reinforced the existing medieval fortifications. The Beck Bastion - named after the Governor Baron Johann von Beck, a Luxembourger who had played a key role on the side of the Emperor in the Wallenstein affair - was built under the supervision of the Swiss fortress builder Issac von Treybach. The bastion was raised to it's current height of 27 meters (the same height as Constitution Square) in 1685.
The Spaniards also built in "Ravelin du Pâvé" which stregthened the Beck Bastion and this triangular fortification is one of the best preserved fortifications in Luxembourg.
After the French laid seige to and conquered Luxembourg, Marshall Vaubin redesigned and strengthened the defences of the city which provided much of the present shape of the Beck Bastion. Vaubin was also responsible for the building the "Small Staircaase." The Austrians added the "Bourbon Lock" and the "Large Staircase" and the 54 gun emplacements of the "Pétrusse Battery were added in 1746. Over the following century the fortress was enlarged and reinforced through the addition of a second ring and a third ring was started.
After the Second Treaty of London, in which Luxembourg was declared neutral, much of the Casemates were dismantled and the loopholes and entrances walled up.