Near the boulevard of Kijkduin, under the dunes, lies is a hidden tunnel system; a part of the complexWiderstandsnest 67 HL. Most of this huge complex was demolished for the construction of the mall and the underlying flats. However, in the dunes behind the NH Atlantic still remains approximately one hundred thirty six meter tunnel connected bunkers. In this portion of the complex was among other things, the Flugwache,a part of the Luftwaffe that had to search the skies for enemy aircrafts.
Since 2015 the tunnel system is open for visitors. For safety reasons, the visitors will always be accompanied by a guide. You don't need to book for these guided tours, the groups will be formed on site.