Like so many hills in this area, Cannerberg is also dotted with underground passageways as a result of centuries of limestone mining.
The quarries in the Cannerberg have more than other quarries a rich war history. This started on a larger scale during the Second World War, when the Germans set up a secret workshop and launch site for V1 rockets in the Cannerberg.
After the war, part of the quarry became an 'ultra-secret' part of the Netherlands, because until 1990 a NATO headquarters was established here. The complex has been subject to the State Secrets Act since 1956.
When tensions mounted in 1963 because of the Cold War, the headquarters was permanently occupied with about three to four hundred troops present during the day.
Dutch, Belgian, British, German and American soldiers manned it day and night in case of war. In 1992 NATO left the quarry.
Today you can take a guided tour, where you can dive into the impressive underground structures. For example, the middle corridor was renamed Main Street and the rest of the corridors were given names from the NATO alphabet.
As in many Cold War air raid shelters, overpressure was used to ensure that hazardous substances could be kept out in the event of a nuclear, biological or chemical attack.
In addition to four hundred offices, two restaurants and a hair salon, there was even a 3-hole golf course with artificial grass.
