This fascinating museum was a secret subterranean fortress used in the 20th-century Cold War era, when nuclear war was a feared possibility in the bellicose stand-off between NATO and the USSR. Visits are by 90-minute guided tours (in Danish, but with a few audio guides available in English and German). You don't need to join a guided tour to explore the above-ground area, which displays a selection of rocket launchers, mobile radar stations and container-box control rooms.
For 75kr you can drive a model tank (get a token from the visitor centre).
If doing the full 1.7km Stevnsfort tour, it's worth bringing warm clothes as you'll be 18m underground, where the temperature hovers around 10°C. Booking ahead is wise as groups are limited to 30 people and some days there are only one or two departures (most commonly 11am, 1pm and/or 3pm). Click KØB BILLET on the website to see a calendar of available tour times.
The site is 3km south of Stevns Klint, halfway between Højerup and Rødvig, and a pleasant coastal walk from Gamle Kirke.