The clearance of the vast majority of Denmark’s minefields during 1945 was remarkable. In just under five months, a force ranging between 750 and 2,600 German prisoners of war (POW) under the supervision of 250–350 Danish officers and noncommissioned officers cleared 1,389,281 mines from an area of 1,103.2 sq km (425.9 sq mi). Such speed of clearance stands in stark contrast with much of modern humanitarian mine action since the 1990s. This article will explain how such speed was possible and why it could not reasonably be repeated today. The article will also identify a number of important lessons that remain to be learned.