Mysterious stone building: Where do the materials for Rastatt Fortress come from?

Mysterious stone building: Where do the materials for Rastatt Fortress come from?

What does Rastatt Fortress have to do with the wall stones? An interesting question that is taken up in the current BNN summer puzzle 2025. Under the motto “Baden underground” the focus is on a particularly mysterious part of the fortress: the casemates of the Rastatt Federal Fortress. These are located within Bastion 27, which was once equipped with a large gun emplacement and housed a total of twelve cannons. But what many people don't know is that the entrance to these historic casemates is small and easy to miss, which makes them all the more exciting.

The Rastatt Fortress, built between 1842 and 1852, was created with a clear goal: to surround and defend the city as protection against the French. In total, the fortress comprised 30 buildings, with more than 50 buildings originally planned, but not all of them were realized. However, their military importance was limited. After the Franco-Prussian War (1870/71) it lost its relevance and was finally abandoned in 1890 and largely demolished in the following years. bnn.de reports that some parts of the fortress such as the Kehler Gate, the Karlsruher Gate and various casemates have been preserved to this day.

A look into history

The construction of the fortress was no small undertaking. On November 3, 1815, the idea of ​​building a fourth federal fortress on the Upper Rhine was decided, financed by 20 million French francs. The first plans were drawn up between 1819 and 1824, but were not implemented for two decades due to political tensions. It was not until 1841 that the Federal Assembly commissioned the construction of Rastatt and another fortress in Ulm. Rastatt was designated as a strategically important location for the VIII Army Corps, with the intention of serving as a communication and border fortress. By 1844, 4,000 workers were already employed on the construction site, and the first stones came from a red sand quarry on Eichelberg, transported via a 14.5 kilometer long horse-drawn tram.

The fortress began operations in 1848, but was interrupted the following year during the Baden Revolution. Dramatic scenes took place this year - the Rastatt casemates were the scene of mutinies that were ultimately put down by the Prussian troops. After a short interruption, work was resumed in 1850 and then provisionally completed in 1852. Interestingly, in the event of war, the fortress could hold up to 30,000 men!

The summer puzzle and its challenge

There are currently questions surrounding the historical origins of building materials. As part of the summer puzzle, you can try to find out where most of the stones used to build the fortress came from. There are four options to choose from: Is it the quarry at Leisberg in Baden-Baden, on-site mining in Rastatt, the Buntsand quarry at Eichelberg near Oberweier or perhaps a quarry in Bavaria? The solution submission deadline is August 28, 2025 at 2 p.m. and solutions can be submitted by phone, online or via email. So it's worth staying tuned because the winners will be announced on Friday evening, August 29th. And who knows, maybe the next puzzle on Sunday evening, August 31st, will have equally exciting surprises in store?

Rastatt Fortress remains a fascinating relic of history and not only offers interesting insights into times gone by, but also exciting puzzles for the present. Until then, everyone can have a good hand and visit the narrow entrances of the casemates to experience the historical depth of the Rastatt Fortress for themselves. If you would like to find out more about it, you can contact the Rastatt Historical Association, which regularly offers guided tours.