Traditionally, the position of Nijmegen on a lateral moraine and by a large river has been of major strategic importance. This was no different during the Second World War. As early as in the 1930s, when the threat of war from the east increased ever more, the Dutch Army took precautions. For example, measures were taken to be able to defend the bridges. Roadblocks were placed on the newly opened Waal bridge, and three casemates were constructed at Lent. The German occupier did not underestimate the importance of the Waal bridges either. On the south side of the bridge, underneath the Valkhofpark, a bunker was built that can still be visited today. The north side of the bridge was defended as well.

A German investigation into the boundaries of the Third Reich in 1943 showed that they did not offer sufficient protection to the Reich. As a measure the Westwall, a line of defence that ran along the southwestern German border, was constructed.  In the region around Nijmegen, the Westwall was moved further to the west to make use of the natural advantages of the lateral moraine. Placing a firm roadblock on the bridge was part of this operation. 5 concrete blocks were placed on a foundation that was almost 22 metres long and 1.25 metres wide. The blocks were 2 metres high.

During Operation Market Garden, the roadblocks – together with the other defences at the bridge – presented a significant obstacle to the Allies, even though thanks to several messages from the resistance, this did not come as a surprise. In the end, the Allies managed to overcome the obstacles and after the successful capture of the bridges the roadblocks were removed, buried and forgotten, until they were dug up again when work was carried out on site in 2013.

That there must have been some sort of roadblock there during the Second World War was expected, but finding back the big concrete blocks nevertheless came as a surprise. Today, they can be found just a few metres from their original location.