Rubjerg Knude Lighthouse was built in 1900, and its light was the lit the 27th of December of that year. Between the years of 1910 and 1920, the drifting sands became such a big problem that bushes and trees were planted to help improve the conditions in the area. Despite this effort, the sand dune only grew larger, and the sand started to cover the plants. In the 50's most of the plants were removed again and a lot of sand was removed from the area, as it got to close to the lighthouse buildings. In the end, the sand dunes became so vast it covered the light of the lighthouse, but by this time new navigation technologies were abundant, the light was on for the last time on August 1st 1968. https://www.visitnordjylland.com/north-jutland/things-do/rubjerg-knude-lighthouse