Visit the old WW2 bunkers on Rømø. Guided tours in German and Danish. It starts by a presentation in Tønnisgård when you drive or cycle in your own vehicle to the first bunker. You visit four bunkers. The two last ones are a bit challenging. You have to climb ladders and move in narrow shafts. Bring a good flashlight (they have a few extra for people who did not bring a flashlight) and shoes that can take some water.