Most bunkers are locked. At these 26 places you can go inside, on a guided tour or an open day. Opening times are on their own sites, because they change with the season.
Bunker van de Tigerstelling bij het museum. Photo fotograaf onbekend, CC0.West-TerschellingIn the Tigerstellung, the German radar position in the dunes above West-Terschelling.
Bunker van de Atlantikwall bij IJmuiden. Photo Arwin Meijer, CC BY-SA 3.0.IJmuidenBunkers of the German defences around the harbour, open to look inside.
De geschutsbunker van het museum. Photo Ymblanter, CC BY-SA 4.0.Hoek van HollandA bunker complex in the dunes by the Nieuwe Waterweg, with a gun out front.
De observatiepost in het museum. Photo Zandcee, CC BY-SA 4.0.Noordwijk aan ZeeBunkers in the dunes at Noordwijk, furnished and open on set days.
Kazemat op Kornwerderzand. Photo Archangel12, CC BY 2.0.KornwerderzandThe casemates on the Afsluitdijk, where fighting went on for days in May 1940.
Bunkermuseum Bunker 1, Vlissingen. Photo Zandcee, CC BY-SA 4.0.Vlissingen en WalcherenLooks after and opens bunkers on Walcheren, including Vlissingen and Zoutelande.
Het reduit van Fort bij Vechten. Photo HenkvD, CC BY-SA 3.0 nl.BunnikAn underground museum in a fort of the New Dutch Water Line.
Bunker bij Fort Kijkduin. Photo truncator, CC BY 3.0.Huisduinen, Den HelderA coastal fort from Napoleon's day, with wartime bunkers around it.
A Luftwaffe radar command centre, one of the few still standing.
A German bunker in the Valkhof park, open to visitors on set days.
Bunker bij Clingendael, Wassenaar. Photo Tukka, CC BY-SA 4.0.WassenaarVolunteers who open up bunkers in the dunes at Wassenaar.
Not a bunker museum, but the same years: the air war over the Zaan region.
A Second World War museum at Huisduinen, in the concrete of Festung Den Helder.
Bunkers under the dunes of Scheveningen, part of the fortress that ran straight through The Hague.
A cluster of bunkers in the dunes between Egmond and Bergen.
A bunker in the dunes at Egmond aan Zee, opened up by volunteers.
Widerstandsnest 12H in the dunes of Vlieland.
A bunker on Schiermonnikoog, part of the German radar position on the island.
A bunker at Hollum on Ameland, part of the Ameland museums.
An 1881 coastal fort on the Nieuwe Waterweg, absorbed into the Atlantic Wall during the war.
Visitor centre for the Grebbe Line, with casemates and trenches in the surroundings.
A casemate of the Grebbe Line near Leusden, fitted out as a museum.
The bunkers of the IJssel Line near Olst: command bunker, Bofors bunker and quad-gun bunker.
On the air war over North Holland, in a fort of the Defence Line of Amsterdam.
On the air war and the occupation of Texel, next to De Vlijt airfield.
On the bombing of the dyke in 1944 and the landing on Walcheren.
Museum missing? Let us know and we will add it.